$NWBI
Northwest Bancshares, Inc. Stock $nwbi

$nwbi Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000147126521000039 Filed on February 26, 2021

Income Statement

Concept	2020 Q4	2019 Q4	2019 Q3
Revenue	$111.7M	$103.4M	$106.9M
YoY Change	8.04%	5.78%	11.78%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin			$4.570M
YoY Change			-16.25%
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	-$1.900M	$2.900M	-$500.0K
YoY Change	-165.52%	480.0%	-155.56%
% of Gross Profit
Operating Expenses			$4.570M
YoY Change			-16.25%
Operating Profit
YoY Change
Interest Expense	$8.841M	$14.47M	$15.93M
YoY Change	-38.91%	32.33%	62.75%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$44.39M	$32.36M	$43.21M
YoY Change	37.16%	-4.85%	24.25%
Income Tax	$9.327M	$6.773M	$9.793M
% Of Pretax Income	21.01%	20.93%	22.67%
Net Earnings	$35.10M	$25.60M	$33.40M
YoY Change	37.11%	-3.4%	20.58%
Net Earnings / Revenue	31.42%	24.75%	31.25%
Basic Earnings Per Share	$0.28	$0.24	$0.32
Diluted Earnings Per Share	$0.28	$0.24	$0.31
COMMON SHARES
Basic Shares Outstanding	127.8M shares	106.7M shares	105.5M shares
Diluted Shares Outstanding			106.3M shares

Balance Sheet

Concept	2020 Q4	2019 Q4	2019 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments		$898.7M
YoY Change		0.64%
Cash & Equivalents	$736.3M	$60.85M	$107.6M
Short-Term Investments		$837.9M
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$161.5M	$147.4M	$148.8M
YoY Change	9.58%	2.8%	2.89%
Goodwill	$382.3M	$346.1M	$344.7M
YoY Change	10.45%	12.58%	12.13%
Intangibles	$19.94M	$23.08M	$22.41M
YoY Change	-13.61%	16.42%	5.87%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$13.81B	$10.49B	$10.58B
YoY Change	31.56%	9.22%	10.5%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$2.000M	$1.000M	$1.000M
YoY Change	100.0%	0.0%	0.0%
Accrued Expenses		$52.00M	$52.00M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$159.7M	$246.3M
YoY Change	-35.16%	5.1%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$2.000M	$53.00M	$53.00M
YoY Change	-96.23%	5200.0%	5200.0%
LONG-TERM LIABILITIES
Long-Term Debt	$412.0M	$368.0M	$377.0M
YoY Change	11.96%	6.36%	30.0%
Other Long-Term Liabilities	$254.0M	$127.0M	$117.0M
YoY Change	100.0%	15.45%	30.0%
Total Long-Term Liabilities	$666.0M	$495.0M	$494.0M
YoY Change	34.55%	8.55%	30.0%
TOTAL LIABILITIES
Total Short-Term Liabilities	$2.000M	$53.00M	$53.00M
Total Long-Term Liabilities	$666.0M	$495.0M	$494.0M
Total Liabilities	$12.27B	$9.141B	$9.229B
YoY Change	34.21%	9.47%	10.73%
SHAREHOLDERS EQUITY
Retained Earnings	$555.5M	$583.4M	$577.0M
YoY Change	-4.79%	6.0%	6.57%
Common Stock	$1.017B	$806.8M	$802.4M
YoY Change	26.02%	8.01%	7.87%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.539B	$1.353B	$1.352B
YoY Change
Total Liabilities & Shareholders Equity	$13.81B	$10.49B	$10.58B
YoY Change	31.56%	9.22%	10.5%

Cashflow Statement

Concept	2020 Q4	2019 Q4	2019 Q3
OPERATING ACTIVITIES
Net Income	$35.10M	$25.60M	$33.40M
YoY Change	37.11%	-3.4%	20.58%
Depreciation, Depletion And Amortization	-$1.900M	$2.900M	-$500.0K
YoY Change	-165.52%	480.0%	-155.56%
Cash From Operating Activities	-$13.40M	$16.80M	$29.70M
YoY Change	-179.76%	-48.31%	-25.19%
INVESTING ACTIVITIES
Capital Expenditures	-$1.500M	-$1.600M	-$2.800M
YoY Change	-6.25%	-11.11%	64.71%
Acquisitions
YoY Change
Other Investing Activities	$83.20M	$32.50M	-$58.90M
YoY Change	156.0%	-194.48%	-25.25%
Cash From Investing Activities	$81.70M	$30.90M	-$61.70M
YoY Change	164.4%	-185.36%	-23.45%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	11.20M	-94.40M	32.50M
YoY Change	-111.86%	6193.33%	-279.56%
NET CHANGE
Cash From Operating Activities	-13.40M	16.80M	29.70M
Cash From Investing Activities	81.70M	30.90M	-61.70M
Cash From Financing Activities	11.20M	-94.40M	32.50M
Net Change In Cash	79.50M	-46.70M	500.0K
YoY Change	-270.24%	798.08%	-100.85%
FREE CASH FLOW
Cash From Operating Activities	-$13.40M	$16.80M	$29.70M
Capital Expenditures	-$1.500M	-$1.600M	-$2.800M
Free Cash Flow	-$11.90M	$18.40M	$32.50M
YoY Change	-164.67%	-46.36%	-21.5%

Facts In Submission

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CY2020	dei	Entity File Number EntityFileNumber	001-34582
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CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	MD
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CY2020	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	15728000	USD
CY2019	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	14133000	USD
CY2018	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	14139000	USD
CY2020	nwbi	Noninterest Expense Collection Of Receivables NoninterestExpenseCollectionOfReceivables	3275000	USD
CY2019	nwbi	Noninterest Expense Collection Of Receivables NoninterestExpenseCollectionOfReceivables	2560000	USD
CY2018	nwbi	Noninterest Expense Collection Of Receivables NoninterestExpenseCollectionOfReceivables	2209000	USD
CY2020	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	50050000	USD
CY2019	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	42453000	USD
CY2018	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	39046000	USD
CY2020	us-gaap	Marketing Expense MarketingExpense	7695000	USD
CY2019	us-gaap	Marketing Expense MarketingExpense	6998000	USD
CY2018	us-gaap	Marketing Expense MarketingExpense	8434000	USD
CY2020	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	4767000	USD
CY2019	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	685000	USD
CY2018	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	2746000	USD
CY2020	us-gaap	Professional Fees ProfessionalFees	12482000	USD
CY2019	us-gaap	Professional Fees ProfessionalFees	12287000	USD
CY2018	us-gaap	Professional Fees ProfessionalFees	10598000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6856000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6543000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5848000	USD
CY2020	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	359000	USD
CY2019	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	478000	USD
CY2018	us-gaap	Foreclosed Real Estate Expense ForeclosedRealEstateExpense	817000	USD
CY2020	nwbi	Restructuring And Acquisition Related Costs RestructuringAndAcquisitionRelatedCosts	20789000	USD
CY2019	nwbi	Restructuring And Acquisition Related Costs RestructuringAndAcquisitionRelatedCosts	4168000	USD
CY2018	nwbi	Restructuring And Acquisition Related Costs RestructuringAndAcquisitionRelatedCosts	1014000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	16494000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	13995000	USD
CY2018	us-gaap	Other Noninterest Expense OtherNoninterestExpense	11333000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	347492000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	296103000	USD
CY2018	us-gaap	Noninterest Expense NoninterestExpense	276098000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	92526000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	141111000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	133913000	USD
CY2020	nwbi	Federal Tax Expense Benefit FederalTaxExpenseBenefit	14896000	USD
CY2019	nwbi	Federal Tax Expense Benefit FederalTaxExpenseBenefit	24069000	USD
CY2018	nwbi	Federal Tax Expense Benefit FederalTaxExpenseBenefit	21948000	USD
CY2020	nwbi	State And Local Tax Expense Benefit StateAndLocalTaxExpenseBenefit	2776000	USD
CY2019	nwbi	State And Local Tax Expense Benefit StateAndLocalTaxExpenseBenefit	6610000	USD
CY2018	nwbi	State And Local Tax Expense Benefit StateAndLocalTaxExpenseBenefit	6474000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17672000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30679000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28422000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	74854000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	110432000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	105491000	USD
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.62
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.05
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.03
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.62
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.04
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.02
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	74854000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	110432000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	105491000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	5607000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	3990000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-513000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	13711000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	9984000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-1277000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	6000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	2000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	60000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	15000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	5000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	155000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	13696000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	9979000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-1432000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-209000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-946000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	-209000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	-223000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	-946000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	-840000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	840000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-4169000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-3193000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-770000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-11301000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-8059000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-1181000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	395000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	334000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	746000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	997000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	835000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	903000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	10304000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	7224000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	278000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	3392000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	2755000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-870000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	78246000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	113187000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	104621000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	1207724000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	105491000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-374000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-870000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	104621000	USD
CY2018	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	8191000	USD
CY2018	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	7023000	USD
CY2018	us-gaap	Stock Granted During Period Value Sharebased Compensation Forfeited StockGrantedDuringPeriodValueSharebasedCompensationForfeited	0	USD
CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.68
CY2018	us-gaap	Dividends Cash DividendsCash	69921000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	1257638000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	110432000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	1129000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	2755000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	113187000	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	43288000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	9727000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	6845000	USD
CY2019	us-gaap	Stock Granted During Period Value Sharebased Compensation Forfeited StockGrantedDuringPeriodValueSharebasedCompensationForfeited	1000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.72
CY2019	us-gaap	Dividends Cash DividendsCash	76173000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	1353285000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	74854000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	1287000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	3392000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	78246000	USD
CY2020	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	213406000	USD
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1479000	USD
CY2020	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	9276000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	4239000	USD
CY2020	us-gaap	Stock Granted During Period Value Sharebased Compensation Forfeited StockGrantedDuringPeriodValueSharebasedCompensationForfeited	0	USD
CY2020	us-gaap	Noncontrolling Interest Increase From Business Combination NoncontrollingInterestIncreaseFromBusinessCombination	105000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.76
CY2020	us-gaap	Dividends Cash DividendsCash	93132000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	1538703000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	74854000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	110432000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	105491000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	83975000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	22659000	USD
CY2018	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	20332000	USD
CY2020	us-gaap	Gains Losses On Sales Of Assets GainsLossesOnSalesOfAssets	3249000	USD
CY2019	us-gaap	Gains Losses On Sales Of Assets GainsLossesOnSalesOfAssets	2472000	USD
CY2018	us-gaap	Gains Losses On Sales Of Assets GainsLossesOnSalesOfAssets	-1677000	USD
CY2020	us-gaap	Gain Loss On Sale Of Properties GainLossOnSaleOfProperties	25798000	USD
CY2019	us-gaap	Gain Loss On Sale Of Properties GainLossOnSaleOfProperties	0	USD
CY2018	us-gaap	Gain Loss On Sale Of Properties GainLossOnSaleOfProperties	0	USD
CY2020	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	4738000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	3824000	USD
CY2018	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	8120000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	16097000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	66080000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	6428000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	47018000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	53998000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-1129000	USD
CY2020	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-3797000	USD
CY2019	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-922000	USD
CY2018	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-1871000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	4239000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	6845000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	7023000	USD
CY2020	us-gaap	Impairment Of Real Estate ImpairmentOfRealEstate	321000	USD
CY2019	us-gaap	Impairment Of Real Estate ImpairmentOfRealEstate	607000	USD
CY2018	us-gaap	Impairment Of Real Estate ImpairmentOfRealEstate	1518000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-8084000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2776000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2770000	USD
CY2020	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	729939000	USD
CY2019	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	68400000	USD
CY2018	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	1297000	USD
CY2020	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	704660000	USD
CY2019	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	62351000	USD
CY2018	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	4501000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	140435000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	127462000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	138909000	USD
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	164629000	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	USD
CY2018	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	830487000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	200204000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	228180000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	3760000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	4707000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	6892000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	392511000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	241079000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	210362000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1096000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	32389000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	5206000	USD
CY2020	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	596000	USD
CY2019	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	2638000	USD
CY2018	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	2730000	USD
CY2020	nwbi	Originations Of Loans Receivable Held For Investment OriginationsOfLoansReceivableHeldForInvestment	4655969000	USD
CY2019	nwbi	Originations Of Loans Receivable Held For Investment OriginationsOfLoansReceivableHeldForInvestment	3721001000	USD
CY2018	nwbi	Originations Of Loans Receivable Held For Investment OriginationsOfLoansReceivableHeldForInvestment	3002810000	USD
CY2020	nwbi	Proceeds From Maturities And Principal Reductions On Loans ProceedsFromMaturitiesAndPrincipalReductionsOnLoans	4383933000	USD
CY2019	nwbi	Proceeds From Maturities And Principal Reductions On Loans ProceedsFromMaturitiesAndPrincipalReductionsOnLoans	3275400000	USD
CY2018	nwbi	Proceeds From Maturities And Principal Reductions On Loans ProceedsFromMaturitiesAndPrincipalReductionsOnLoans	2726103000	USD
CY2020	us-gaap	Proceeds From Sale Of Loans Held For Investment ProceedsFromSaleOfLoansHeldForInvestment	50791000	USD
CY2019	us-gaap	Proceeds From Sale Of Loans Held For Investment ProceedsFromSaleOfLoansHeldForInvestment	97923000	USD
CY2018	us-gaap	Proceeds From Sale Of Loans Held For Investment ProceedsFromSaleOfLoansHeldForInvestment	0	USD
CY2020	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	-6107000	USD
CY2019	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	-1348000	USD
CY2018	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	3902000	USD
CY2020	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	1651000	USD
CY2019	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	4198000	USD
CY2018	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	6312000	USD
CY2020	us-gaap	Proceeds From Sale Of Real Estate Heldforinvestment ProceedsFromSaleOfRealEstateHeldforinvestment	607000	USD
CY2019	us-gaap	Proceeds From Sale Of Real Estate Heldforinvestment ProceedsFromSaleOfRealEstateHeldforinvestment	608000	USD
CY2018	us-gaap	Proceeds From Sale Of Real Estate Heldforinvestment ProceedsFromSaleOfRealEstateHeldforinvestment	607000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	12254000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	10899000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	5233000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	-261712000	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	28779000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-560575000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-300593000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-281913000	USD
CY2020	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	1390187000	USD
CY2019	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	218449000	USD
CY2018	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	67190000	USD
CY2018	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	8190000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	9276000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1095571000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	165188000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	134083000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	675431000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-7943000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-8921000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	60846000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	68789000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	77710000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	675431000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-7943000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-8921000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	736277000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	60846000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	68789000	USD
CY2020	nwbi	Cash Paid For Interest On Deposits CashPaidForInterestOnDeposits	34313000	USD
CY2019	nwbi	Cash Paid For Interest On Deposits CashPaidForInterestOnDeposits	44928000	USD
CY2018	nwbi	Cash Paid For Interest On Deposits CashPaidForInterestOnDeposits	29330000	USD
CY2020	nwbi	Cash Paid For Interest On Deposits And Borrowings CashPaidForInterestOnDepositsAndBorrowings	41428000	USD
CY2019	nwbi	Cash Paid For Interest On Deposits And Borrowings CashPaidForInterestOnDepositsAndBorrowings	54277000	USD
CY2018	nwbi	Cash Paid For Interest On Deposits And Borrowings CashPaidForInterestOnDepositsAndBorrowings	36856000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	29767000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	29283000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	25849000	USD
CY2020	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	2090599000	USD
CY2019	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	584253000	USD
CY2018	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	0	USD
CY2020	us-gaap	Stock Issued1 StockIssued1	213406000	USD
CY2019	us-gaap	Stock Issued1 StockIssued1	43288000	USD
CY2018	us-gaap	Stock Issued1 StockIssued1	0	USD
CY2020	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	45600000	USD
CY2018	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	0	USD
CY2020	us-gaap	Noncash Or Part Noncash Acquisition Net Nonmonetary Assets Acquired Liabilities Assumed1 NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1	1877193000	USD
CY2019	us-gaap	Noncash Or Part Noncash Acquisition Net Nonmonetary Assets Acquired Liabilities Assumed1 NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1	495365000	USD
CY2018	us-gaap	Noncash Or Part Noncash Acquisition Net Nonmonetary Assets Acquired Liabilities Assumed1 NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1	0	USD
CY2020	nwbi	Transfer Of Other Real Estate And Other Repossessed Personal Property TransferOfOtherRealEstateAndOtherRepossessedPersonalProperty	5643000	USD
CY2019	nwbi	Transfer Of Other Real Estate And Other Repossessed Personal Property TransferOfOtherRealEstateAndOtherRepossessedPersonalProperty	5815000	USD
CY2018	nwbi	Transfer Of Other Real Estate And Other Repossessed Personal Property TransferOfOtherRealEstateAndOtherRepossessedPersonalProperty	7181000	USD
CY2020	nwbi	Sale And Financing Of Other Real Estate Owned SaleAndFinancingOfOtherRealEstateOwned	126000	USD
CY2019	nwbi	Sale And Financing Of Other Real Estate Owned SaleAndFinancingOfOtherRealEstateOwned	44000	USD
CY2018	nwbi	Sale And Financing Of Other Real Estate Owned SaleAndFinancingOfOtherRealEstateOwned	296000	USD
CY2020Q4	nwbi	Number Of Banking Locations NumberOfBankingLocations	170	bank_location
CY2020	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	segment
CY2020Q4	us-gaap	Trading Securities TradingSecurities	0	USD
CY2019Q4	us-gaap	Trading Securities TradingSecurities	0	USD
CY2020	nwbi	Debt Securities Held To Maturity Accrued Interest Receivable DebtSecuritiesHeldToMaturityAccruedInterestReceivable	1800000	USD
CY2019	nwbi	Debt Securities Held To Maturity Accrued Interest Receivable DebtSecuritiesHeldToMaturityAccruedInterestReceivable	1500000	USD
CY2020	nwbi	Debt Securities Available For Sale Accrued Interest Receivable DebtSecuritiesAvailableForSaleAccruedInterestReceivable	1900000	USD
CY2019	nwbi	Debt Securities Available For Sale Accrued Interest Receivable DebtSecuritiesAvailableForSaleAccruedInterestReceivable	900000	USD
CY2020	nwbi	Financing Receivable Accrued Interest Receivable FinancingReceivableAccruedInterestReceivable	31700000	USD
CY2019	nwbi	Financing Receivable Accrued Interest Receivable FinancingReceivableAccruedInterestReceivable	23300000	USD
CY2020Q4	nwbi	Financing Receivable Accrued Interest Received Current FinancingReceivableAccruedInterestReceivedCurrent	4400000	USD
CY2020	nwbi	Financing Receivable Number Of Days Delinquency For Accrued Interest On Loans To Be Considered Reversal FinancingReceivableNumberOfDaysDelinquencyForAccruedInterestOnLoansToBeConsideredReversal	P90D
CY2020	nwbi	Financing Receivable Number Of Days Delinquent For Loans To Be Placed On Nonaccrual Status FinancingReceivableNumberOfDaysDelinquentForLoansToBePlacedOnNonaccrualStatus	P90D
CY2020	nwbi	Period To Return Troubled Debt Restructured Loans Included In Non Performing Loans To Performing Status PeriodToReturnTroubledDebtRestructuredLoansIncludedInNonPerformingLoansToPerformingStatus	P180D
CY2020Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	58800000	USD
CY2019Q4	us-gaap	Mortgages Held For Sale Fair Value Disclosure MortgagesHeldForSaleFairValueDisclosure	7700000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Policy For Uncollectible Amounts FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts	Allowance for Credit Losses and Provision for Credit Losses<div style="text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> </span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses is deducted from, or added to, the loan’s amortized cost basis to present the net amount expected to be collected on our lending portfolios. We estimate the allowance balance using relevant available information, from internal and external sources, relating to past events, current conditions and reasonable and supportable forecasts. Loans are charged off against the allowance when we believe the uncollectibility of a loan balance is confirmed. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Expected credit losses are estimated over the contractual term of the loans, adjusted for prepayments. The contractual term excludes expected extensions, renewals and modifications unless we had a reasonable expectation at the reporting date that a TDR will be executed for an individual borrower or the extension or renewal option is included in the contract and is not unconditionally cancellable by the Company. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Credit card receivables do not have stated maturities. In determining the estimated life of a credit card receivable, we first estimate the future cash flows expected to be received and then apply those expected future cash flows to the credit card balance. Expected credit losses for credit cards are determined by estimating the amount and timing of principal payments expected to be </span></div><div style="text-align:justify"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">received as payment for the balance outstanding as of the reporting date and applying those principal payments against the balance outstanding as of the reporting period until the expected payments have been fully allocated. The allowance for credit losses is recorded for the excess of the balance outstanding as of the reporting period over the expected principal payments. </span></div><div style="text-align:justify"><span><br/></span></div><div style="text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:115%">The allowance for credit losses is measured on a collective ("pool") basis when similar risk characteristics exist. </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:115%">For the purpose of calculating portfolio-level reserves, we have grouped our loans into seven segments: residential mortgage loans, home equity loans, vehicle loans, consumer loans, commercial real estate loans, commercial real estate owner-occupied and commercial loans. The allowance for credit losses is measured at the pool level utilizing loan-level inputs wherever possible. We use a twelve-month forecasting period and revert to historical average loss rates thereafter. The reasonable and supportable forecast is based on a probability-weighted multiple economic scenario approach and obtained from a third party vendor. Reversion to the mean takes place over a twelve-month period. Our loss rate models utilize a linear reversion method. For our Probability of Default ("PD")/Loss Given Default ("LDG") models we revert the PD utilizing exponential reversion, which is an accelerated method, and the LGD utilizing a linear reversion method. Historical average loss rates are calculated using historical data beginning in 2009 through the current period. As part of the analysis as of December 31, 2020, we considered the most recent economic conditions and forecasts available which incorporated the impact of COVID-19. The ACL increased in the period largely attributable to COVID-19. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Mortgage and Home Equity Loans</span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses within the mortgage and home equity loan classes is calculated at the pool-level using a non-discounted cash flow method through a PD and LGD model developed by an external third-party. These classes are further divided into smaller pools of loans with similar risk characteristics such as: lines versus loans, fixed versus variable, senior lien position versus junior lien position, among other things.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For each pool, the models project default rates, prepayment rates, and severity rates. The models accept as inputs key risk drivers such as: current balance, original credit bureau score, original loan-to-value ratio, type of collateral, location of collateral, delinquency status, loan age, among other characteristics. They also utilize macroeconomic forecasts of home price indices, unemployment rates, gross domestic product, and others.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%"> </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Vehicle Loans</span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> </span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> The allowance for credit losses within the vehicle loan portfolio is calculated at the portfolio-level using a non-discounted cash flow method through a loss rate model developed internally with the assistance of an external third-party. The allowance for vehicle loans utilizes a vintage analysis to project portfolio-level net charge-off rates. The class is further divided into short term versus long term loans, prime versus subprime borrowers, and origination vintage. This model uses current balance, original credit bureau score, original debt-to-income ratio, loan term, loan age, and other product characteristics as key risk drivers. </span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The model used for vehicle loans is not natively sensitive to macroeconomic conditions. The necessary adjustments to account for current and expected macroeconomic conditions is captured via our qualitative adjustment framework.</span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%"> Consumer Loans</span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses within the consumer loan portfolio is calculated at the portfolio-level using a non-discounted cash flow method through a suite of loss rate models developed internally with the assistance of an external third-party. This </span><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">class of financing receivables is </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">further divided into credit cards, unsecured lines of credit and other consumer loans.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses for credit cards and unsecured lines of credit is calculated using two transition matrix models to project portfolio-level net charge-off rates. Both models use current balance and delinquency status as key risk drivers. These models are not natively sensitive to macroeconomic conditions. The necessary adjustments to account for current and expected macroeconomic conditions is captured via our qualitative adjustment framework.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For other consumer loans, a regression model is used to project portfolio-level net charge-off rates. This model uses borrower information and macroeconomic forecasts as key inputs.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%"> </span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Commercial Real Estate Loans</span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The commercial real estate loan class is further segmented into smaller pools of loans with similar risk characteristics, commercial real estate loans and small business commercial real estate loans. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses for the commercial real estate loan portfolio is calculated at the pool level using a non-discounted cash flow method through a PD/LGD model developed by an external third-party. This model projects default and severity rates. The model accepts as inputs key risk drivers such as: current balance, original loan-to-value-ratio, type of collateral, location of collateral, delinquency status, loan age, obligor financial statement information, and expected prepayment rates, among other characteristics. It also utilizes macroeconomic forecasts of commercial real estate price indices, unemployment rates, gross domestic product and others. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses is calculated for commercial real estate small business loans at the portfolio-level using a non-discounted cash flow method through a loss rate model developed internally with the assistance of an external third-party. A regression model is used to project portfolio-level net charge-off rates. This model uses loan characteristics and macroeconomic forecasts as key inputs.</span></div><div><span><br/></span></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%"> </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Commercial Loans and Commercial Real Estate - Owner Occupied Loans</span></div><div style="text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses for the commercial loan portfolio and the commercial real estate - owner occupied loan portfolio is calculated at the pool level using a non-discounted cash flow method through a PD/LGD model developed by an external third-party. The commercial loan class is further segmented into smaller pools of loans with similar risk characteristics, commercial loans and commercial small business loans. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The commercial loan portfolio and the commercial real estate owner occupied loan portfolio models project default and severity rates. The model accepts as inputs key risk drivers such as the obligor financial statement information, collateral type, the obligor’s primary industry, expected prepayment rates, among other characteristics. It also utilizes macroeconomic forecasts of unemployment rates, gross domestic product, corporate bond spreads, and others.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses for commercial small business loans is calculated at the portfolio-level using a non-discounted cash flow method through a loss rate model developed internally with the assistance of an external third-party. A regression model is used to project portfolio-level net charge-off rates. This model uses loan characteristics and macroeconomic forecasts as key inputs.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Loans that do not share risk characteristics are evaluated on an individual basis. Loans evaluated individually are not also included in the collective evaluation. When we determine that foreclosure is probable or when the borrower is experiencing financial difficulty at the reporting date and repayment is expected to be provided substantially through the operation or sale of the collateral, expected credit losses are based on the fair value of the collateral at the reporting date, adjusted for selling costs. If this criteria is not met, a discounted cash flow method is used to determine the allowance for credit losses. All changes in the discounted cash flow method over time are reported in the allowance for credit losses. </span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance calculation is also supplemented with qualitative reserves that takes into consideration the current portfolio and specific risk characteristics, such as changes in underwriting standards, portfolio mix, delinquency level, or term, as well as changes in environmental conditions, among other factors, that have occurred but are not yet reflected in the quantitative model component. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses on a TDR is measured using the same method as all other loans held for investment, except when the value of the concession cannot be measured using a method other than the discounted cash flow method. When the value of a concession is measured using the discounted cash flow method, the allowance for credit losses is determined by discounting the expected future cash flows at the original interest rate of the loan. </span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For off-balance-sheet credit exposures, we estimate expected credit losses over the contractual period in which we are exposed to credit risk via a contractual obligation to extend credit, unless that obligation is unconditionally cancellable. The liability for credit losses on off-balance-sheet credit exposures is adjusted through a provision for credit loss expense and is included within "other expenses". We estimate the liability balance using relevant available information, from internal and external sources, relating to past events, current conditions and reasonable and supportable forecasts. The estimate includes a consideration of the likelihood that </span></div><div style="text-align:justify"><span style="color:#212529;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated life. Off-balance-sheet exposures that are not unconditionally cancellable have been identified for the home equity, commercial real estate, and commercial loan portfolios. </span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Results for reporting periods beginning after January 1, 2020 are presented under CECL methodology while prior period amounts continue to be reported in accordance with Accounting Standards Codification (“ASC”) Topic 450, Contingencies; and specific reserves based upon ASC Topic 310, Receivables. ASC Topic 450 applies to homogeneous loan pools such as commercial loans, consumer lines of credit and residential mortgages that are not individually evaluated for impairment. ASC Topic 310 is applied to commercial and consumer loans that are individually evaluated for impairment.</span></div>
CY2020Q4	nwbi	Number Of Loan Segments NumberOfLoanSegments	7	segment
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum	0.031
CY2020	us-gaap	Use Of Estimates UseOfEstimates	Use of EstimatesThe preparation of financial statements, in conformity with accounting principles generally accepted in the United States of America, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amount of revenues and expenses during the reporting period. The estimates and assumptions that we deem important to our financial statements relate to the allowance for loan losses, the accounting treatment and valuation of our investment securities portfolio, the analysis of the carrying value of goodwill, pension and income taxes. These estimates and assumptions are based on management’s best estimates and judgment and we evaluate them using historical experience and other factors, including the current economic environment. We adjust our estimates and assumptions when facts and circumstances dictate. As future events cannot be determined, actual results could differ significantly from our estimates.
CY2020	us-gaap	Comparability Of Prior Year Financial Data ComparabilityOfPriorYearFinancialData	Reclassification of Prior Years’ Statements<div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> </span></div><div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Certain items previously reported have been reclassified to conform with the current year’s reporting format.</span></div>
CY2020Q2	nwbi	Business Combination Consideration Transferred Cash Paid In Lieu Of Fractional Shares Share Price BusinessCombinationConsiderationTransferredCashPaidInLieuOfFractionalSharesSharePrice	10.71
CY2020Q2	nwbi	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loans Receivable Discount BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansReceivableDiscount	14700000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	6139000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	5603000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	680000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	596000	USD
CY2020	us-gaap	Lease Cost LeaseCost	6819000	USD
CY2019	us-gaap	Lease Cost LeaseCost	6199000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	48329000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	49380000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	52206000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	52092000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	6204000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	5564000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	8657000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	13268000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P15Y1M6D
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P15Y8M12D
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.034
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.037
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	6079000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	5681000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	5403000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	4731000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	4521000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	41882000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	68297000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	16091000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	52206000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	5692000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	5362000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	5042000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	4734000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	4408000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	44758000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	69996000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	17904000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	52092000	USD
CY2020	us-gaap	Lease Cost LeaseCost	6800000	USD
CY2019	us-gaap	Lease Cost LeaseCost	6200000	USD
CY2018	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	5400000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1375685000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	24702000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1446000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	123211000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	0	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	206908000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	0	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	0	USD
CY2020	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-108675000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	11947000	USD
CY2018	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	126151000	USD
CY2020	us-gaap	Increase Decrease In Advance Payments By Borrowers For Taxes And Insurance IncreaseDecreaseInAdvancePaymentsByBorrowersForTaxesAndInsurance	-1315000	USD
CY2019	us-gaap	Increase Decrease In Advance Payments By Borrowers For Taxes And Insurance IncreaseDecreaseInAdvancePaymentsByBorrowersForTaxesAndInsurance	1238000	USD
CY2018	us-gaap	Increase Decrease In Advance Payments By Borrowers For Taxes And Insurance IncreaseDecreaseInAdvancePaymentsByBorrowersForTaxesAndInsurance	2473000	USD
CY2020	us-gaap	Payments Of Dividends PaymentsOfDividends	93132000	USD
CY2019	us-gaap	Payments Of Dividends PaymentsOfDividends	76173000	USD
CY2018	us-gaap	Payments Of Dividends PaymentsOfDividends	69921000	USD
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	1479000	USD
CY2019	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	9727000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1398941000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	178887000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	904000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	125000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	179666000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	815495000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	7351000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	2945000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	819901000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	18036000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	187000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	18223000	USD
CY2020Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses1 HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses1	1460000	USD
CY2020Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	7456000	USD
CY2020Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses	111000	USD
CY2020Q4	us-gaap	Security Owned And Pledged As Collateral Fair Value SecurityOwnedAndPledgedAsCollateralFairValue	160300000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1100000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	64000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	32400000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	29000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	5200000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	189000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	37000	USD
CY2020	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Period Increase Decrease DebtSecuritiesAvailableForSaleAllowanceForCreditLossPeriodIncreaseDecrease	0	USD
CY2018	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	0	USD
CY2019	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	0	USD
CY2020Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	372833000	USD
CY2020Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Fair Value HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	380289000	USD
CY2020Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses1 HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses1	1571000	USD
CY2019Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	173112000	USD
CY2019Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Aggregate Losses1 HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses1	858000	USD
CY2019Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	161944000	USD
CY2019Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Aggregate Losses HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses	2087000	USD
CY2019Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Fair Value HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	335056000	USD
CY2019Q4	nwbi	Held To Maturity And Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses1 HeldToMaturityAndAvailableForSaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses1	2945000	USD
CY2020	nwbi	Number Of Investment Positions With Unrealized Losses NumberOfInvestmentPositionsWithUnrealizedLosses	123	position
CY2020Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	178887000	USD
CY2019	nwbi	Number Of Investment Positions With Unrealized Losses NumberOfInvestmentPositionsWithUnrealizedLosses	119	position
CY2019Q4	us-gaap	Marketable Securities MarketableSecurities	837900000	USD
CY2019	nwbi	Number Of Investment Securities With Otherthan Temporary Impairment NumberOfInvestmentSecuritiesWithOtherthanTemporaryImpairment	0	position
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	10580849000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	8808674000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	134427000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	57941000	USD
CY2020Q4	us-gaap	Notes Receivable Net NotesReceivableNet	10446422000	USD
CY2019Q4	us-gaap	Notes Receivable Net NotesReceivableNet	8750733000	USD
CY2020Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	58800000	USD
CY2019Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	7700000	USD
CY2020Q4	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	40900000	USD
CY2019Q4	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	40200000	USD
CY2020Q4	us-gaap	Derecognized Assets Securitized Or Assetbacked Financing Arrangement Assets And Any Other Financial Assets Managed Together Principal Amount Outstanding DerecognizedAssetsSecuritizedOrAssetbackedFinancingArrangementAssetsAndAnyOtherFinancialAssetsManagedTogetherPrincipalAmountOutstanding	1516000000	USD
CY2019Q4	us-gaap	Derecognized Assets Securitized Or Assetbacked Financing Arrangement Assets And Any Other Financial Assets Managed Together Principal Amount Outstanding DerecognizedAssetsSecuritizedOrAssetbackedFinancingArrangementAssetsAndAnyOtherFinancialAssetsManagedTogetherPrincipalAmountOutstanding	793100000	USD
CY2018Q4	us-gaap	Derecognized Assets Securitized Or Assetbacked Financing Arrangement Assets And Any Other Financial Assets Managed Together Principal Amount Outstanding DerecognizedAssetsSecuritizedOrAssetbackedFinancingArrangementAssetsAndAnyOtherFinancialAssetsManagedTogetherPrincipalAmountOutstanding	794200000	USD
CY2020Q4	nwbi	Percentage Of Financing Receivable Portfolio Secured By Properties PercentageOfFinancingReceivablePortfolioSecuredByProperties	0.42
CY2019Q4	nwbi	Percentage Of Financing Receivable Portfolio Secured By Properties PercentageOfFinancingReceivablePortfolioSecuredByProperties	0.50
CY2020Q4	us-gaap	Loans Receivable With Variable Rates Of Interest1 LoansReceivableWithVariableRatesOfInterest1	3690000000	USD
CY2019Q4	us-gaap	Loans Receivable With Variable Rates Of Interest1 LoansReceivableWithVariableRatesOfInterest1	3090000000.000	USD
CY2020Q4	us-gaap	Loans Receivable With Fixed Rates Of Interest1 LoansReceivableWithFixedRatesOfInterest1	6840000000	USD
CY2019Q4	us-gaap	Loans Receivable With Fixed Rates Of Interest1 LoansReceivableWithFixedRatesOfInterest1	5948000000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	134427000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	83975000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	34718000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	7592000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Loss Purchased With Credit Deterioration Increase FinancingReceivableAllowanceForCreditLossPurchasedWithCreditDeteriorationIncrease	8845000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	57941000	USD
CY2020	us-gaap	Allowance For Loan And Lease Losses Loans Sold AllowanceForLoanAndLeaseLossesLoansSold	50000000.0	USD
CY2020	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	1300000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	57941000	USD
CY2019	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	22659000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	26212000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	6280000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	55214000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	55214000	USD
CY2018	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	20332000	USD
CY2018	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	29641000	USD
CY2018	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	7728000	USD
CY2017Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	56795000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	10580849000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	134427000	USD
CY2020Q4	nwbi	Financing Receivable Nonaccrual Including Nonaccrual With No Allowance FinancingReceivableNonaccrualIncludingNonaccrualWithNoAllowance	102832000	USD
CY2020Q4	nwbi	Financing Receivable Recorded Investment90 Days Or More Past Maturity And Still Accruing FinancingReceivableRecordedInvestment90DaysOrMorePastMaturityAndStillAccruing	585000	USD
CY2020Q4	nwbi	Financing Receivable Troubled Debt Restructuring Excluding Nonaccrual FinancingReceivableTroubledDebtRestructuringExcludingNonaccrual	32135000	USD
CY2020Q4	nwbi	Financing Receivable Allowance For Credit Loss Modifications FinancingReceivableAllowanceForCreditLossModifications	2016000	USD
CY2020Q4	nwbi	Financing Receivable Modifications Recorded Investment Additional Commitment FinancingReceivableModificationsRecordedInvestmentAdditionalCommitment	859000	USD
CY2020Q4	nwbi	Financing Receivable Modifications Recorded Investment Non Accrual FinancingReceivableModificationsRecordedInvestmentNonAccrual	10700000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	8808674000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	57941000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	68870000	USD
CY2019Q4	nwbi	Financing Receivable Recorded Investment90 Days Or More Past Maturity And Still Accruing FinancingReceivableRecordedInvestment90DaysOrMorePastMaturityAndStillAccruing	32000	USD
CY2019Q4	nwbi	Financing Receivable Troubled Debt Restructuring Excluding Nonaccrual FinancingReceivableTroubledDebtRestructuringExcludingNonaccrual	31999000	USD
CY2019Q4	nwbi	Financing Receivable Allowance For Credit Loss Modifications FinancingReceivableAllowanceForCreditLossModifications	3002000	USD
CY2019Q4	nwbi	Financing Receivable Modifications Recorded Investment Additional Commitment FinancingReceivableModificationsRecordedInvestmentAdditionalCommitment	566000	USD
CY2019Q4	nwbi	Financing Receivable Modifications Recorded Investment Non Accrual FinancingReceivableModificationsRecordedInvestmentNonAccrual	9000000.0	USD
CY2020Q1	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	68870000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	79992000	USD
CY2020Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	22840000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	585000	USD
CY2020	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	842000	USD
CY2020Q4	nwbi	Financing Receivable Amortized Cost Of Collateral Dependent Loans FinancingReceivableAmortizedCostOfCollateralDependentLoans	99039000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	105993000	USD
CY2019	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	88643000	USD
CY2019	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	3070000	USD
CY2019Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	8739372000	USD
CY2019Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	69302000	USD
CY2019Q4	nwbi	Financing Receivable Individually Evaluated For Impairment Reserved FinancingReceivableIndividuallyEvaluatedForImpairmentReserved	57999000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	11762000	USD
CY2019Q4	nwbi	Financing Receivable Individually Evaluated For Impairment Not Reserved FinancingReceivableIndividuallyEvaluatedForImpairmentNotReserved	11303000	USD
CY2018Q4	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	98283000	USD
CY2018	us-gaap	Impaired Financing Receivable Average Recorded Investment ImpairedFinancingReceivableAverageRecordedInvestment	84338000	USD
CY2018	us-gaap	Impaired Financing Receivable Interest Income Accrual Method ImpairedFinancingReceivableInterestIncomeAccrualMethod	3762000	USD
CY2018Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	7997835000	USD
CY2018Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	53604000	USD
CY2018Q4	nwbi	Financing Receivable Individually Evaluated For Impairment Reserved FinancingReceivableIndividuallyEvaluatedForImpairmentReserved	48875000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	8542000	USD
CY2018Q4	nwbi	Financing Receivable Individually Evaluated For Impairment Not Reserved FinancingReceivableIndividuallyEvaluatedForImpairmentNotReserved	4729000	USD
CY2019Q4	nwbi	Financing Receivable Modifications Outstanding Number Of Contracts FinancingReceivableModificationsOutstandingNumberOfContracts	176	contract
CY2019Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	31999000	USD
CY2018Q4	nwbi	Financing Receivable Modifications Outstanding Number Of Contracts FinancingReceivableModificationsOutstandingNumberOfContracts	195	contract
CY2018Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	33608000	USD
CY2020	nwbi	Financing Receivable Modifications Number Of Contracts2 Additions FinancingReceivableModificationsNumberOfContracts2Additions	14	contract
CY2020	nwbi	Financing Receivable Modifications Recorded Investment Additions FinancingReceivableModificationsRecordedInvestmentAdditions	1497000	USD
CY2019	nwbi	Financing Receivable Modifications Number Of Contracts2 Additions FinancingReceivableModificationsNumberOfContracts2Additions	14	contract
CY2019	nwbi	Financing Receivable Modifications Recorded Investment Additions FinancingReceivableModificationsRecordedInvestmentAdditions	3344000	USD
CY2020	nwbi	Financing Receivable Modifications Number Of Contracts Remodified FinancingReceivableModificationsNumberOfContractsRemodified	5	contract
CY2020	nwbi	Financing Receivable Modifications Recorded Investment Re Modifications FinancingReceivableModificationsRecordedInvestmentReModifications	9693000	USD
CY2019	nwbi	Financing Receivable Modifications Number Of Contracts Remodified FinancingReceivableModificationsNumberOfContractsRemodified	8	contract
CY2019	nwbi	Financing Receivable Modifications Recorded Investment Re Modifications FinancingReceivableModificationsRecordedInvestmentReModifications	5678000	USD
CY2020	nwbi	Financing Receivable Modifications Number Of Contracts Net Paydowns FinancingReceivableModificationsNumberOfContractsNetPaydowns	0	USD
CY2020	nwbi	Financing Receivable Modifications Recorded Investment Net Paydowns FinancingReceivableModificationsRecordedInvestmentNetPaydowns	9806000	USD
CY2019	nwbi	Financing Receivable Modifications Number Of Contracts Net Paydowns FinancingReceivableModificationsNumberOfContractsNetPaydowns	0	USD
CY2019	nwbi	Financing Receivable Modifications Recorded Investment Net Paydowns FinancingReceivableModificationsRecordedInvestmentNetPaydowns	7806000	USD
CY2020Q4	nwbi	Financing Receivable Modifications Outstanding Number Of Contracts FinancingReceivableModificationsOutstandingNumberOfContracts	170	contract
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	32135000	USD
CY2019Q4	nwbi	Financing Receivable Modifications Outstanding Number Of Contracts FinancingReceivableModificationsOutstandingNumberOfContracts	176	contract
CY2019Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	31999000	USD
CY2020Q4	nwbi	Financing Receivable Modifications Recorded Investment Accrual FinancingReceivableModificationsRecordedInvestmentAccrual	21431000	USD
CY2019Q4	nwbi	Financing Receivable Modifications Recorded Investment Accrual FinancingReceivableModificationsRecordedInvestmentAccrual	22956000	USD
CY2020Q4	nwbi	Financing Receivable Modifications Recorded Investment Non Accrual FinancingReceivableModificationsRecordedInvestmentNonAccrual	10704000	USD
CY2019Q4	nwbi	Financing Receivable Modifications Recorded Investment Non Accrual FinancingReceivableModificationsRecordedInvestmentNonAccrual	9043000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	18	contract
CY2020	nwbi	Financing Receivable Modification That Subsequently Defaulted Pre Modification Recorded Investment FinancingReceivableModificationThatSubsequentlyDefaultedPreModificationRecordedInvestment	10543000	USD
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	8238000	USD
CY2020	nwbi	Increase Decrease In Financing Receivable Modifications Recorded Investment Reserve IncreaseDecreaseInFinancingReceivableModificationsRecordedInvestmentReserve	373000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	22	contract
CY2019	nwbi	Financing Receivable Modification That Subsequently Defaulted Pre Modification Recorded Investment FinancingReceivableModificationThatSubsequentlyDefaultedPreModificationRecordedInvestment	9022000	USD
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	8023000	USD
CY2019	nwbi	Increase Decrease In Financing Receivable Modifications Recorded Investment Reserve IncreaseDecreaseInFinancingReceivableModificationsRecordedInvestmentReserve	665000	USD
CY2018	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	35000	contract
CY2018	nwbi	Financing Receivable Modification That Subsequently Defaulted Pre Modification Recorded Investment FinancingReceivableModificationThatSubsequentlyDefaultedPreModificationRecordedInvestment	4886000	USD
CY2018	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	4815000	USD
CY2018	nwbi	Increase Decrease In Financing Receivable Modifications Recorded Investment Reserve IncreaseDecreaseInFinancingReceivableModificationsRecordedInvestmentReserve	460000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	18	contract
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	8238000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	22	contract
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	8023000	USD
CY2020	nwbi	Financing Receivable Modifications Number Of Contracts Remodified FinancingReceivableModificationsNumberOfContractsRemodified	5	contract
CY2020	nwbi	Financing Receivable Remodifications Post Modification Recorded Investment FinancingReceivableRemodificationsPostModificationRecordedInvestment	6780000	USD
CY2019	nwbi	Financing Receivable Modifications Number Of Contracts Remodified FinancingReceivableModificationsNumberOfContractsRemodified	8	contract
CY2019	nwbi	Financing Receivable Remodifications Post Modification Recorded Investment FinancingReceivableRemodificationsPostModificationRecordedInvestment	4705000	USD
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	contract
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	135022000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	10445827000	USD
CY2020Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	10580849000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	585000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	119401000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	8689273000	USD
CY2019Q4	us-gaap	Financing Receivable Before Allowance For Credit Loss And Fee FinancingReceivableBeforeAllowanceForCreditLossAndFee	8808674000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	147000	USD
CY2020Q4	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	2430289000	USD
CY2020Q4	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	1729845000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	1128885000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	919058000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	689542000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	2616425000	USD
CY2020Q4	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	916515000	USD
CY2020Q4	us-gaap	Financing Receivable Revolving Converted To Term Loan FinancingReceivableRevolvingConvertedToTermLoan	150290000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	10580849000	USD
CY2020	nwbi	Financing Receivable Revolving Converted To Term Loan During The Period FinancingReceivableRevolvingConvertedToTermLoanDuringThePeriod	23100000	USD
CY2020Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1341106000	USD
CY2019Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Amount Liability FairValueDisclosureOffbalanceSheetRisksAmountLiability	1191601000	USD
CY2018Q4	nwbi	Servicing Asset At Amortized Value Gross ServicingAssetAtAmortizedValueGross	2103000	USD
CY2018Q4	us-gaap	Valuation Allowance For Impairment Of Recognized Servicing Assets Balance ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance	0	USD
CY2018Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	2103000	USD
CY2019	nwbi	Servicing Asset At Amortized Cost.Additions Gross ServicingAssetAtAmortizedCost.AdditionsGross	862000	USD
CY2019	us-gaap	Valuation Allowance For Impairment Of Recognized Servicing Assets Provisions Recoveries ValuationAllowanceForImpairmentOfRecognizedServicingAssetsProvisionsRecoveries	1000	USD
CY2019	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	861000	USD
CY2019	nwbi	Servicing Assets At Amortized Cost Amortization Gross ServicingAssetsAtAmortizedCostAmortizationGross	1117000	USD
CY2019	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	1117000	USD
CY2019Q4	nwbi	Servicing Asset At Amortized Value Gross ServicingAssetAtAmortizedValueGross	1848000	USD
CY2019Q4	us-gaap	Valuation Allowance For Impairment Of Recognized Servicing Assets Balance ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance	1000	USD
CY2019Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	1847000	USD
CY2020	nwbi	Servicing Asset At Amortized Cost.Additions Gross ServicingAssetAtAmortizedCost.AdditionsGross	9549000	USD
CY2020	us-gaap	Valuation Allowance For Impairment Of Recognized Servicing Assets Provisions Recoveries ValuationAllowanceForImpairmentOfRecognizedServicingAssetsProvisionsRecoveries	491000	USD
CY2020	us-gaap	Servicing Asset At Amortized Value Additions ServicingAssetAtAmortizedValueAdditions	9058000	USD
CY2020	nwbi	Servicing Assets At Amortized Cost Amortization Gross ServicingAssetsAtAmortizedCostAmortizationGross	2740000	USD
CY2020	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	2740000	USD
CY2020Q4	nwbi	Servicing Asset At Amortized Value Gross ServicingAssetAtAmortizedValueGross	8657000	USD
CY2020Q4	us-gaap	Valuation Allowance For Impairment Of Recognized Servicing Assets Balance ValuationAllowanceForImpairmentOfRecognizedServicingAssetsBalance	492000	USD
CY2020Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	8165000	USD
CY2020	us-gaap	Financing Receivable Purchased With Credit Deterioration Amount At Purchase Price FinancingReceivablePurchasedWithCreditDeteriorationAmountAtPurchasePrice	244546000	USD
CY2020	us-gaap	Financing Receivable Purchased With Credit Deterioration Allowance For Credit Loss At Acquisition Date FinancingReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLossAtAcquisitionDate	8845000	USD
CY2020	us-gaap	Financing Receivable Purchased With Credit Deterioration Discount Premium FinancingReceivablePurchasedWithCreditDeteriorationDiscountPremium	-4154000	USD
CY2020	us-gaap	Financing Receivable Purchased With Credit Deterioration Amount At Par Value FinancingReceivablePurchasedWithCreditDeteriorationAmountAtParValue	239855000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	755000	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	551000	USD
CY2019	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsFromNonaccretableDifference	966000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield	1170000	USD
CY2020Q4	nwbi	Accrued Interest Receivable On Investments AccruedInterestReceivableOnInvestments	1660000	USD
CY2019Q4	nwbi	Accrued Interest Receivable On Investments AccruedInterestReceivableOnInvestments	730000	USD
CY2020Q4	nwbi	Accrued Interest Receivable On Fhld Dividends AccruedInterestReceivableOnFHLDDividends	197000	USD
CY2019Q4	nwbi	Accrued Interest Receivable On Fhld Dividends AccruedInterestReceivableOnFHLDDividends	211000	USD
CY2020Q4	nwbi	Accrued Interest Receivable On Mortgage Backed Securities AccruedInterestReceivableOnMortgageBackedSecurities	2031000	USD
CY2019Q4	nwbi	Accrued Interest Receivable On Mortgage Backed Securities AccruedInterestReceivableOnMortgageBackedSecurities	1508000	USD
CY2020Q4	nwbi	Accrued Interest Receivable On Loans AccruedInterestReceivableOnLoans	31666000	USD
CY2019Q4	nwbi	Accrued Interest Receivable On Loans AccruedInterestReceivableOnLoans	23306000	USD
CY2020Q4	us-gaap	Interest Receivable InterestReceivable	35554000	USD
CY2019Q4	us-gaap	Interest Receivable InterestReceivable	25755000	USD
CY2020	nwbi	Federal Home Loan Bank Stock Dividend Received FederalHomeLoanBankStockDividendReceived	981400	USD
CY2019	nwbi	Federal Home Loan Bank Stock Dividend Received FederalHomeLoanBankStockDividendReceived	1100000	USD
CY2020Q4	nwbi	Number Of Subclasses Of Federal Home Loan Bank Of Pittsburgh Capital Stock Required To Invest In For Membership NumberOfSubclassesOfFederalHomeLoanBankOfPittsburghCapitalStockRequiredToInvestInForMembership	2	subclass
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	334983000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	321715000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	173445000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	174306000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	161538000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	147409000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11900000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	11700000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	12100000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	19936000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	23076000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5848000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6543000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6856000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	5902000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	4680000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	3592000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	2692000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	1819000	USD
CY2019Q4	us-gaap	Interest Bearing Domestic Deposit Checking InterestBearingDomesticDepositChecking	1944108000	USD
CY2020Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	2437539000	USD
CY2019Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	1863998000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	307420000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	38683000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	346103000	USD
CY2020	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	36176000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	382279000	USD
CY2019Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	0	USD
CY2020Q4	us-gaap	Goodwill Impaired Accumulated Impairment Loss GoodwillImpairedAccumulatedImpairmentLoss	0	USD
CY2020Q4	us-gaap	Noninterest Bearing Domestic Deposit Checking NoninterestBearingDomesticDepositChecking	2716224000	USD
CY2019Q4	us-gaap	Noninterest Bearing Domestic Deposit Checking NoninterestBearingDomesticDepositChecking	1609653000	USD
CY2020Q4	us-gaap	Interest Bearing Domestic Deposit Checking InterestBearingDomesticDepositChecking	2755950000	USD
CY2020Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	2047424000	USD
CY2019Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1604838000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	1642096000	USD
CY2019Q4	us-gaap	Time Deposits TimeDeposits	1569410000	USD
CY2020Q4	us-gaap	Deposits Deposits	11599233000	USD
CY2019Q4	us-gaap	Deposits Deposits	8592007000	USD
CY2020Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	578500000	USD
CY2019Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	521100000	USD
CY2020Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	3744000000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	990769000	USD
CY2019Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	909509000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	380466000	USD
CY2019Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	300656000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	164583000	USD
CY2019Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	214301000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	64700000	USD
CY2019Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	106065000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	36098000	USD
CY2019Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	35358000	USD
CY2020Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	5480000	USD
CY2019Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	3521000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	1642096000	USD
CY2019Q4	us-gaap	Time Deposits TimeDeposits	1569410000	USD
CY2020	us-gaap	Interest Expense Domestic Deposit Liabilities Checking InterestExpenseDomesticDepositLiabilitiesChecking	3358000	USD
CY2019	us-gaap	Interest Expense Domestic Deposit Liabilities Checking InterestExpenseDomesticDepositLiabilitiesChecking	6012000	USD
CY2018	us-gaap	Interest Expense Domestic Deposit Liabilities Checking InterestExpenseDomesticDepositLiabilitiesChecking	3607000	USD
CY2020	us-gaap	Interest Expense Money Market Deposits InterestExpenseMoneyMarketDeposits	7021000	USD
CY2019	us-gaap	Interest Expense Money Market Deposits InterestExpenseMoneyMarketDeposits	13010000	USD
CY2018	us-gaap	Interest Expense Money Market Deposits InterestExpenseMoneyMarketDeposits	5740000	USD
CY2020	us-gaap	Interest Expense Savings Deposits InterestExpenseSavingsDeposits	2614000	USD
CY2019	us-gaap	Interest Expense Savings Deposits InterestExpenseSavingsDeposits	3115000	USD
CY2018	us-gaap	Interest Expense Savings Deposits InterestExpenseSavingsDeposits	3064000	USD
CY2020	us-gaap	Interest Expense Time Deposits InterestExpenseTimeDeposits	22903000	USD
CY2019	us-gaap	Interest Expense Time Deposits InterestExpenseTimeDeposits	27079000	USD
CY2018	us-gaap	Interest Expense Time Deposits InterestExpenseTimeDeposits	18574000	USD
CY2020	us-gaap	Interest Expense Deposits InterestExpenseDeposits	35896000	USD
CY2019	us-gaap	Interest Expense Deposits InterestExpenseDeposits	49216000	USD
CY2018	us-gaap	Interest Expense Deposits InterestExpenseDeposits	30985000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	283044000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	246336000	USD
CY2020Q2	nwbi	Number Of Business Trusts Owned NumberOfBusinessTrustsOwned	5	business_trust
CY2020Q2	nwbi	Number Of Business Trusts Acquired After Merger NumberOfBusinessTrustsAcquiredAfterMerger	2	business_trust
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17672000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30679000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28422000	USD
CY2020	nwbi	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Available For Sale Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesAvailableForSaleArisingDuringPeriodTax	5061000	USD
CY2019	nwbi	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Available For Sale Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesAvailableForSaleArisingDuringPeriodTax	3992000	USD
CY2018	nwbi	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Available For Sale Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesAvailableForSaleArisingDuringPeriodTax	-573000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	3774000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	2859000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	24000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	223000	USD
CY2020	nwbi	Income Tax Expense Benefit Unallocated IncomeTaxExpenseBenefitUnallocated	18959000	USD
CY2019	nwbi	Income Tax Expense Benefit Unallocated IncomeTaxExpenseBenefitUnallocated	31812000	USD
CY2018	nwbi	Income Tax Expense Benefit Unallocated IncomeTaxExpenseBenefitUnallocated	28048000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	25756000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	27903000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	31192000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-8084000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2776000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2770000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	17672000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30679000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28422000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.017
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.008
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.009
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.022
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.037
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.038
CY2020	nwbi	Effective Income Tax Rate Reconciliation Tax Exempt Income Related To Bank Owned Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeRelatedToBankOwnedLifeInsurancePercent	0.011
CY2019	nwbi	Effective Income Tax Rate Reconciliation Tax Exempt Income Related To Bank Owned Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeRelatedToBankOwnedLifeInsurancePercent	0.006
CY2018	nwbi	Effective Income Tax Rate Reconciliation Tax Exempt Income Related To Bank Owned Life Insurance Percent EffectiveIncomeTaxRateReconciliationTaxExemptIncomeRelatedToBankOwnedLifeInsurancePercent	0.009
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	-0.002
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	0.006
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Percent EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent	0.008
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0.009
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0.006
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends EffectiveIncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	0.006
CY2020	nwbi	Effective Income Tax Rate Reconciliation Low Income Housing And Historic Tax Credits EffectiveIncomeTaxRateReconciliationLowIncomeHousingAndHistoricTaxCredits	0.009
CY2019	nwbi	Effective Income Tax Rate Reconciliation Low Income Housing And Historic Tax Credits EffectiveIncomeTaxRateReconciliationLowIncomeHousingAndHistoricTaxCredits	0.005
CY2018	nwbi	Effective Income Tax Rate Reconciliation Low Income Housing And Historic Tax Credits EffectiveIncomeTaxRateReconciliationLowIncomeHousingAndHistoricTaxCredits	0.006
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.003
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.001
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.002
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.191
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.217
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.212
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	4272000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	1974000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	30418000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	12609000	USD
CY2020Q4	nwbi	Deferred Tax Assets Other Reserves DeferredTaxAssetsOtherReserves	2358000	USD
CY2019Q4	nwbi	Deferred Tax Assets Other Reserves DeferredTaxAssetsOtherReserves	961000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	778000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	436000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	820000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	994000	USD
CY2020Q4	nwbi	Deferred Tax Assets Expense Compensation And Pension Benefits And Other Postretirement Benefits DeferredTaxAssetsExpenseCompensationAndPensionBenefitsAndOtherPostretirementBenefits	19405000	USD
CY2019Q4	nwbi	Deferred Tax Assets Expense Compensation And Pension Benefits And Other Postretirement Benefits DeferredTaxAssetsExpenseCompensationAndPensionBenefitsAndOtherPostretirementBenefits	15916000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	540000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	728000	USD
CY2020Q4	nwbi	Deferred Tax Assets Operating Lease Liabilities DeferredTaxAssetsOperatingLeaseLiabilities	11713000	USD
CY2019Q4	nwbi	Deferred Tax Assets Operating Lease Liabilities DeferredTaxAssetsOperatingLeaseLiabilities	11493000	USD
CY2020Q4	nwbi	Deferred Tax Assets Purchase Accounting DeferredTaxAssetsPurchaseAccounting	412000	USD
CY2019Q4	nwbi	Deferred Tax Assets Purchase Accounting DeferredTaxAssetsPurchaseAccounting	0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	2800000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	504000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	1338000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	626000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	74854000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	46241000	USD
CY2020Q4	nwbi	Deferred Tax Liabilities Pension Costs DeferredTaxLiabilitiesPensionCosts	6198000	USD
CY2019Q4	nwbi	Deferred Tax Liabilities Pension Costs DeferredTaxLiabilitiesPensionCosts	5864000	USD
CY2020Q4	nwbi	Deferred Tax Liabilities Purchase Accounting DeferredTaxLiabilitiesPurchaseAccounting	0	USD
CY2019Q4	nwbi	Deferred Tax Liabilities Purchase Accounting DeferredTaxLiabilitiesPurchaseAccounting	291000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	15419000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	14464000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	1831000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	407000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	4740000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	5755000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Deferred Expense DeferredTaxLiabilitiesDeferredExpense	1548000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Deferred Expense DeferredTaxLiabilitiesDeferredExpense	5042000	USD
CY2020Q4	nwbi	Deferred Tax Liabilities Operating Lease Right Of Use Assets DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets	10844000	USD
CY2019Q4	nwbi	Deferred Tax Liabilities Operating Lease Right Of Use Assets DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets	10895000	USD
CY2020Q4	nwbi	Deferred Tax Liabilities Unrealized Gains On Available For Sale Securities DeferredTaxLiabilitiesUnrealizedGainsOnAvailableForSaleSecurities	6332000	USD
CY2019Q4	nwbi	Deferred Tax Liabilities Unrealized Gains On Available For Sale Securities DeferredTaxLiabilitiesUnrealizedGainsOnAvailableForSaleSecurities	1259000	USD
CY2020Q4	nwbi	Interest Rate Derivatives InterestRateDerivatives	1268000	USD
CY2019Q4	nwbi	Interest Rate Derivatives InterestRateDerivatives	0	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2670000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	314000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	50850000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	44291000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	24004000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	1950000	USD
CY2020Q4	us-gaap	Deferred Tax Liability Not Recognized Amount Of Unrecognized Deferred Tax Liability Bad Debt Reserve For Tax Purposes Of Qualified Lender DeferredTaxLiabilityNotRecognizedAmountOfUnrecognizedDeferredTaxLiabilityBadDebtReserveForTaxPurposesOfQualifiedLender	3100000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	336000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	5000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsIncreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	0	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	331000	USD
CY2019Q4	us-gaap	Bad Debt Reserve For Tax Purposes Of Qualified Lender BadDebtReserveForTaxPurposesOfQualifiedLender	39100000	USD
CY2020Q4	us-gaap	Bad Debt Reserve For Tax Purposes Of Qualified Lender BadDebtReserveForTaxPurposesOfQualifiedLender	39100000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	74854000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	110432000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	105491000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	120244474	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	104878774	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	102073888	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	960375	shares
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1492013	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	120244474	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	105839149	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	103565901	shares
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.62
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.05
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.03
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.62
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.04
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.02
CY2020	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	1
CY2020	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.04
CY2020Q3	nwbi	Defined Benefit Plan Soft Freeze Hours Threshold DefinedBenefitPlanSoftFreezeHoursThreshold	1000	hour
CY2020	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	8200000	USD
CY2019	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	6700000	USD
CY2018	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	5800000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Amortization Of Gain Loss Next Fiscal Year DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear	4000000.0	USD
CY2019Q4	us-gaap	Defined Benefit Plan Expected Amortization Of Gain Loss Next Fiscal Year DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear	-2300000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	216712000	USD
CY2020Q4	nwbi	Defined Benefit Plan Plan Assets Amount Including Accrued Interest And Dividends DefinedBenefitPlanPlanAssetsAmountIncludingAccruedInterestAndDividends	216900000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	193361000	USD
CY2019Q4	nwbi	Defined Benefit Plan Plan Assets Amount Including Accrued Interest And Dividends DefinedBenefitPlanPlanAssetsAmountIncludingAccruedInterestAndDividends	193500000	USD
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	9.71
CY2020Q4	nwbi	Capital Required To Be Well Capitalized Capital Conservation Buffer CapitalRequiredToBeWellCapitalizedCapitalConservationBuffer	0.025
CY2019Q4	nwbi	Capital Required To Be Well Capitalized Capital Conservation Buffer CapitalRequiredToBeWellCapitalizedCapitalConservationBuffer	0.025
CY2020	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	1464000	USD
CY2020	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-1928000	USD
CY2020	us-gaap	Aoci Including Portion Attributable To Noncontrolling Interest Period Increase Decrease AociIncludingPortionAttributableToNoncontrollingInterestPeriodIncreaseDecrease	3392000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	5607000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-209000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-4169000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	6000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	-209000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	395000	USD
CY2019	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	1925000	USD
CY2019	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-830000	USD
CY2019	us-gaap	Aoci Including Portion Attributable To Noncontrolling Interest Period Increase Decrease AociIncludingPortionAttributableToNoncontrollingInterestPeriodIncreaseDecrease	2755000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	3990000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-3193000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	2000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	334000	USD
CY2018	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-1618000	USD
CY2018	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-748000	USD
CY2018	us-gaap	Aoci Including Portion Attributable To Noncontrolling Interest Period Increase Decrease AociIncludingPortionAttributableToNoncontrollingInterestPeriodIncreaseDecrease	-7616000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-513000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	-223000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-770000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	60000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	746000	USD
CY2020Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	98078000	USD
CY2020Q4	us-gaap	Derivative Asset Notional Amount DerivativeAssetNotionalAmount	796131000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	61433000	USD
CY2020Q4	us-gaap	Derivative Liability Notional Amount DerivativeLiabilityNotionalAmount	676832000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	54665000	USD
CY2019Q4	us-gaap	Derivative Asset Notional Amount DerivativeAssetNotionalAmount	421026000	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	21593000	USD
CY2019Q4	us-gaap	Derivative Liability Notional Amount DerivativeLiabilityNotionalAmount	432666000	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	20991000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	-35000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	949000	USD
CY2020Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	100378000	USD
CY2020Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	108547000	USD
CY2020Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	113414000	USD
CY2020Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	111729000	USD
CY2020Q1	us-gaap	Interest Expense InterestExpense	13150000	USD
CY2020Q2	us-gaap	Interest Expense InterestExpense	10469000	USD
CY2020Q3	us-gaap	Interest Expense InterestExpense	9880000	USD
CY2020Q4	us-gaap	Interest Expense InterestExpense	8841000	USD
CY2020Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	87228000	USD
CY2020Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	103534000	USD
CY2020Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	102888000	USD
CY2020Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	27637000	USD
CY2020Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	51750000	USD
CY2020Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	6818000	USD
CY2020Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-2230000	USD
CY2020Q1	us-gaap	Noninterest Income NoninterestIncome	27976000	USD
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	35496000	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	36670000	USD
CY2020Q4	us-gaap	Noninterest Income NoninterestIncome	32123000	USD
CY2020Q1	us-gaap	Noninterest Expense NoninterestExpense	78611000	USD
CY2020Q2	us-gaap	Noninterest Expense NoninterestExpense	89163000	USD
CY2020Q3	us-gaap	Noninterest Expense NoninterestExpense	86869000	USD
CY2020Q4	us-gaap	Noninterest Expense NoninterestExpense	92849000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	8956000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-7339000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	46517000	USD
CY2020Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	44392000	USD
CY2020Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1017000	USD
CY2020Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-1139000	USD
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	8467000	USD
CY2020Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9327000	USD
CY2020Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	7939000	USD
CY2020Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-6200000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	38050000	USD
CY2020Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	35065000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.08
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.05
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.30
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.28
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.07
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.05
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.30
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.28
CY2019Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	100289000	USD
CY2019Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	106807000	USD
CY2019Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	106866000	USD
CY2019Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	103418000	USD
CY2019Q1	us-gaap	Interest Expense InterestExpense	12307000	USD
CY2019Q2	us-gaap	Interest Expense InterestExpense	14204000	USD
CY2019Q3	us-gaap	Interest Expense InterestExpense	15930000	USD
CY2019Q4	us-gaap	Interest Expense InterestExpense	14473000	USD
CY2019Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	87982000	USD
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	92603000	USD
CY2019Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	90936000	USD
CY2019Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	88945000	USD
CY2019Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	6467000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4667000	USD
CY2019Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	3302000	USD
CY2019Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	8223000	USD
CY2019Q1	us-gaap	Noninterest Income NoninterestIncome	21662000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	23363000	USD
CY2019Q3	us-gaap	Noninterest Income NoninterestIncome	26169000	USD
CY2019Q4	us-gaap	Noninterest Income NoninterestIncome	28213000	USD
CY2019Q1	us-gaap	Noninterest Expense NoninterestExpense	71424000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	77512000	USD
CY2019Q3	us-gaap	Noninterest Expense NoninterestExpense	70596000	USD
CY2019Q4	us-gaap	Noninterest Expense NoninterestExpense	76571000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	31753000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	33787000	USD
CY2019Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	43207000	USD
CY2019Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	32364000	USD
CY2019Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6709000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	7404000	USD
CY2019Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9793000	USD
CY2019Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6773000	USD
CY2019Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	25044000	USD
CY2019Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	26383000	USD
CY2019Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	33414000	USD
CY2019Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	25591000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.24
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.25
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.32
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.24
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.24
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.25
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.31
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.24
CY2018Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	89533000	USD
CY2018Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	92875000	USD
CY2018Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	95605000	USD
CY2018Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	97768000	USD
CY2018Q1	us-gaap	Interest Expense InterestExpense	7766000	USD
CY2018Q2	us-gaap	Interest Expense InterestExpense	8649000	USD
CY2018Q3	us-gaap	Interest Expense InterestExpense	9788000	USD
CY2018Q4	us-gaap	Interest Expense InterestExpense	10937000	USD
CY2018Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	81767000	USD
CY2018Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	84226000	USD
CY2018Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	85817000	USD
CY2018Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	86831000	USD
CY2018Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	4209000	USD
CY2018Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	5349000	USD
CY2018Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	6982000	USD
CY2018Q4	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	3792000	USD
CY2018Q1	us-gaap	Noninterest Income NoninterestIncome	21788000	USD
CY2018Q2	us-gaap	Noninterest Income NoninterestIncome	24109000	USD
CY2018Q3	us-gaap	Noninterest Expense NoninterestExpense	66617000	USD
CY2018Q3	us-gaap	Noninterest Income NoninterestIncome	22557000	USD
CY2018Q4	us-gaap	Noninterest Income NoninterestIncome	23248000	USD
CY2018Q1	us-gaap	Noninterest Expense NoninterestExpense	67421000	USD
CY2018Q2	us-gaap	Noninterest Expense NoninterestExpense	69787000	USD
CY2018Q4	us-gaap	Noninterest Expense NoninterestExpense	72273000	USD
CY2018Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	31925000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	33199000	USD
CY2018Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	34775000	USD
CY2018Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	34014000	USD
CY2018Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6940000	USD
CY2018Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	6900000	USD
CY2018Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	7035000	USD
CY2018Q4	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	7547000	USD
CY2018Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	24985000	USD
CY2018Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	26299000	USD
CY2018Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	27740000	USD
CY2018Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	26467000	USD
CY2018Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.25
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.26
CY2018Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.27
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.26
CY2018Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.24
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.25
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.27
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.26

Files In Submission

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$NWBI
Northwest Bancshares, Inc. Stock $nwbi

2020 Q4 Form 10-K Financial Statement

#000147126521000039 Filed on February 26, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$NWBI Northwest Bancshares, Inc. Stock $nwbi

2020 Q4 Form 10-K Financial Statement

#000147126521000039 Filed on February 26, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$NWBI
Northwest Bancshares, Inc. Stock $nwbi