$NFG
NATIONAL FUEL GAS CO Stock $nfg

$nfg Overview Financials Valuation SEC Filings Company Website

2020 Q3 Form 10-K Financial Statement

#000007014520000032 Filed on November 20, 2020

Income Statement

Concept	2020 Q3	2019 Q3	2019 Q2
Revenue	$288.0M	$293.3M	$357.2M
YoY Change	-1.82%	1.43%	4.17%
Cost Of Revenue	-$5.800M	$4.700M	$47.84M
YoY Change	-223.4%	-68.67%	-8.35%
Gross Profit	$293.8M	$288.6M	$309.4M
YoY Change	1.8%	5.25%	6.42%
Gross Profit Margin	102.02%	98.38%	86.61%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$80.10M	$74.70M	$71.07M
YoY Change	7.23%	18.2%	16.86%
% of Gross Profit	27.26%	25.88%	22.97%
Operating Expenses	$214.4M	$204.7M	$244.4M
YoY Change	4.74%	8.02%	6.76%
Operating Profit	-$174.0M	$83.94M	$112.8M
YoY Change	-307.27%	-0.85%	-1.03%
Interest Expense	-$34.40M	-$26.70M	-$26.50M
YoY Change	28.84%	-9.18%	-6.03%
% of Operating Profit		-31.81%	-23.49%
Other Income/Expense, Net	$200.0K	$1.400M	-$1.456M
YoY Change	-85.71%	-240.0%	-59.69%
Pretax Income	-$208.2M	$58.70M	$84.87M
YoY Change	-454.68%	8.1%	3.23%
Income Tax	-$62.60M	$11.40M	$21.11M
% Of Pretax Income		19.42%	24.88%
Net Earnings	-$145.5M	$47.28M	$63.75M
YoY Change	-407.82%	24.44%	1.16%
Net Earnings / Revenue	-50.54%	16.12%	17.85%
Basic Earnings Per Share	-$1.60	$0.55	$0.74
Diluted Earnings Per Share	-$1.60	$0.54	$0.73
COMMON SHARES
Basic Shares Outstanding	90.95M shares	86.31M shares	86.31M shares
Diluted Shares Outstanding			86.84M shares

Balance Sheet

Concept	2020 Q3	2019 Q3	2019 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments	$20.50M	$20.40M	$87.50M
YoY Change	0.49%	-91.11%	-72.07%
Cash & Equivalents	$20.54M	$20.43M	$87.52M
Short-Term Investments
Other Short-Term Assets	$47.56M	$97.05M	$56.05M
YoY Change	-51.0%	42.68%	6.38%
Inventory	$85.20M	$77.30M	$56.10M
Prepaid Expenses
Receivables	$143.6M	$140.0M	$178.8M
Other Receivables	$3.800M	$50.90M	$15.30M
Total Short-Term Assets	$314.2M	$362.6M	$403.3M
YoY Change	-13.35%	-33.41%	-31.53%
LONG-TERM ASSETS
Property, Plant & Equipment	$5.998B	$5.510B	$5.352B
YoY Change	8.87%	10.7%	10.51%
Goodwill	$5.476M	$5.476M	$5.476M
YoY Change	0.0%	0.0%	0.0%
Intangibles
YoY Change
Long-Term Investments	$154.5M	$144.9M	$137.8M
YoY Change	6.63%	9.36%	5.43%
Other Assets	$81.00K	$80.00K	$42.63M
YoY Change	1.25%	-21.57%	39374.07%
Total Long-Term Assets	$6.651B	$590.0M	$580.6M
YoY Change	1027.2%	14.62%	7.14%
TOTAL ASSETS
Total Short-Term Assets	$314.2M	$362.6M	$403.3M
Total Long-Term Assets	$6.651B	$590.0M	$580.6M
Total Assets	$6.965B	$6.462B	$6.336B
YoY Change	7.78%	7.05%	6.06%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$134.1M	$132.2M	$112.8M
YoY Change	1.45%	-17.39%	0.87%
Accrued Expenses	$140.2M	$139.6M	$180.1M
YoY Change	0.41%	5.21%	372.82%
Deferred Revenue
YoY Change
Short-Term Debt	$30.00M	$55.20M	$0.00
YoY Change	-45.65%
Long-Term Debt Due	$0.00	$0.00	$0.00
YoY Change			-100.0%
Total Short-Term Liabilities	$459.6M	$421.9M	$395.9M
YoY Change	8.93%	-4.12%	-40.14%
LONG-TERM LIABILITIES
Long-Term Debt	$2.630B	$2.134B	$2.133B
YoY Change	23.24%	0.11%	16.21%
Other Long-Term Liabilities	$139.2M	$1.114B	$1.016B
YoY Change	-87.51%	9.76%	-4.0%
Total Long-Term Liabilities	$1.904B	$1.768B	$1.663B
YoY Change	7.71%	15.69%	7.34%
TOTAL LIABILITIES
Total Short-Term Liabilities	$459.6M	$421.9M	$395.9M
Total Long-Term Liabilities	$1.904B	$1.768B	$1.663B
Total Liabilities	$2.363B	$2.189B	$2.059B
YoY Change	7.95%	11.26%	-6.86%
SHAREHOLDERS EQUITY
Retained Earnings	$991.6M	$1.273B	$1.263B
YoY Change	-22.08%	15.81%	15.07%
Common Stock	$90.96M	$86.32M	$86.31M
YoY Change	5.38%	0.42%	0.42%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.972B	$2.139B	$2.144B
YoY Change
Total Liabilities & Shareholders Equity	$6.965B	$6.462B	$6.336B
YoY Change	7.78%	7.05%	6.06%

Cashflow Statement

Concept	2020 Q3	2019 Q3	2019 Q2
OPERATING ACTIVITIES
Net Income	-$145.5M	$47.28M	$63.75M
YoY Change	-407.82%	24.44%	1.16%
Depreciation, Depletion And Amortization	$80.10M	$74.70M	$71.07M
YoY Change	7.23%	18.2%	16.86%
Cash From Operating Activities	$116.9M	$123.9M	$229.8M
YoY Change	-5.65%	27.47%	0.17%
INVESTING ACTIVITIES
Capital Expenditures	-$165.2M	-$201.5M	-$200.8M
YoY Change	-18.01%	11.94%	41.11%
Acquisitions
YoY Change
Other Investing Activities	-$484.6M	-$7.100M	-$500.0K
YoY Change	6725.35%	-607.14%	-101.61%
Cash From Investing Activities	-$649.7M	-$208.7M	-$201.3M
YoY Change	211.31%	16.79%	81.19%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-10.70M	17.60M	-36.60M
YoY Change	-160.8%	-1700.0%	6.71%
NET CHANGE
Cash From Operating Activities	116.9M	123.9M	229.8M
Cash From Investing Activities	-649.7M	-208.7M	-201.3M
Cash From Financing Activities	-10.70M	17.60M	-36.60M
Net Change In Cash	-543.5M	-67.20M	-8.100M
YoY Change	708.78%	-18.64%	-109.64%
FREE CASH FLOW
Cash From Operating Activities	$116.9M	$123.9M	$229.8M
Capital Expenditures	-$165.2M	-$201.5M	-$200.8M
Free Cash Flow	$282.1M	$325.4M	$430.6M
YoY Change	-13.31%	17.39%	15.85%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0000070145
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--09-30
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020	dei	Entity Registrant Name EntityRegistrantName	National Fuel Gas Company
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-09-30
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	1-3880
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	NJ
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	13-1086010
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	6363 Main Street
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Williamsville,
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	NY
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	14221
CY2020	dei	City Area Code CityAreaCode	716
CY2020	dei	Local Phone Number LocalPhoneNumber	857-7000
CY2020	dei	Security12b Title Security12bTitle	Common Stock, par value $1.00 per share
CY2020	dei	Trading Symbol TradingSymbol	NFG
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2020	dei	Entity Small Business EntitySmallBusiness	false
CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2020	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2020	dei	Entity Shell Company EntityShellCompany	false
CY2020Q1	dei	Entity Public Float EntityPublicFloat	3219563000	USD
CY2020	dei	Entity Listing Par Value Per Share EntityListingParValuePerShare	1.00
CY2020Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	90965576	shares
CY2020	us-gaap	Revenues Revenues	1546291000	USD
CY2019	us-gaap	Revenues Revenues	1693332000	USD
CY2018	us-gaap	Revenues Revenues	1592668000	USD
CY2020	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	233890000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	386265000	USD
CY2018	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	337822000	USD
CY2020	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	88400000	USD
CY2019	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	88886000	USD
CY2018	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	84393000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	306158000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	275660000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	240961000	USD
CY2020	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	449438000	USD
CY2019	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	0	USD
CY2018	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	0	USD
CY2020	us-gaap	Costs And Expenses CostsAndExpenses	1516433000	USD
CY2019	us-gaap	Costs And Expenses CostsAndExpenses	1181523000	USD
CY2018	us-gaap	Costs And Expenses CostsAndExpenses	1072945000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	29858000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	511809000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	519723000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-17814000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-15542000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-21174000	USD
CY2020	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	110012000	USD
CY2019	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	101614000	USD
CY2018	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	110946000	USD
CY2020	us-gaap	Interest Expense Other InterestExpenseOther	7065000	USD
CY2019	us-gaap	Interest Expense Other InterestExpenseOther	5142000	USD
CY2018	us-gaap	Interest Expense Other InterestExpenseOther	3576000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-105033000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	389511000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	384027000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18739000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85221000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-7494000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-123772000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	304290000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	391521000	USD
CY2019Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1272601000	USD
CY2018Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1098900000	USD
CY2017Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	851669000	USD
CY2020	nfg	Beginning Retained Earnings Unappropriated And Current Period Net Income Loss BeginningRetainedEarningsUnappropriatedAndCurrentPeriodNetIncomeLoss	1148829000	USD
CY2019	nfg	Beginning Retained Earnings Unappropriated And Current Period Net Income Loss BeginningRetainedEarningsUnappropriatedAndCurrentPeriodNetIncomeLoss	1403190000	USD
CY2018	nfg	Beginning Retained Earnings Unappropriated And Current Period Net Income Loss BeginningRetainedEarningsUnappropriatedAndCurrentPeriodNetIncomeLoss	1243190000	USD
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	156249000	USD
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	148432000	USD
CY2018	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	144290000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	991630000	USD
CY2019Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1272601000	USD
CY2018Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1098900000	USD
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-1.41
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.53
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.56
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.41
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.51
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.53
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	87968895	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	86235550	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85830597	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	87968895	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	86773259	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	86439698	shares
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-123772000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	304290000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	391521000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTax	19214000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTax	44089000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Reclassification Adjustments And Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsAndTax	-6225000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax	15361000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax	7332000	USD
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CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	132000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	9862000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	79301000	USD
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CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	430000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	93295000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-5464000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-1189000	USD
CY2020	nfg	Other Comprehensive Income Loss Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging OtherComprehensiveIncomeLossCumulativeEffectofAdoptionofAuthoritativeGuidanceforHedging	1313000	USD
CY2019	nfg	Other Comprehensive Income Loss Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging OtherComprehensiveIncomeLossCumulativeEffectofAdoptionofAuthoritativeGuidanceforHedging	0	USD
CY2018	nfg	Other Comprehensive Income Loss Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging OtherComprehensiveIncomeLossCumulativeEffectofAdoptionofAuthoritativeGuidanceforHedging	0	USD
CY2020	nfg	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilities	0	USD
CY2019	nfg	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilities	-11738000	USD
CY2018	nfg	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilities	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-85973000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	36270000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-57283000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax	4357000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax	10473000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Before Reclassification Adjustments Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeReclassificationAdjustmentsTax	-1582000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax	3566000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax	1698000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax	2437000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-15000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	2578000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	20619000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-22547000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	158000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	25521000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	-2726000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	955000	USD
CY2020	nfg	Other Comprehensive Income Loss Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging Tax OtherComprehensiveIncomeLossCumulativeEffectofAdoptionofAuthoritativeGuidanceforHedgingTax	363000	USD
CY2019	nfg	Other Comprehensive Income Loss Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging Tax OtherComprehensiveIncomeLossCumulativeEffectofAdoptionofAuthoritativeGuidanceforHedgingTax	0	USD
CY2018	nfg	Other Comprehensive Income Loss Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging Tax OtherComprehensiveIncomeLossCumulativeEffectofAdoptionofAuthoritativeGuidanceforHedgingTax	0	USD
CY2020	nfg	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilitiesTax	0	USD
CY2019	nfg	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilitiesTax	4301000	USD
CY2018	nfg	Other Comprehensive Income Loss Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilitiesTax	0	USD
CY2020	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	0	USD
CY2019	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	-10406000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-23371000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	20675000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-19656000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-62602000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	15595000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-37627000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-186374000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	319885000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	353894000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	12351852000	USD
CY2019Q3	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	11204838000	USD
CY2020Q3	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	6353785000	USD
CY2019Q3	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	5695328000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	5998067000	USD
CY2019Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	5509510000	USD
CY2020Q3	us-gaap	Assets Held For Sale Not Part Of Disposal Group AssetsHeldForSaleNotPartOfDisposalGroup	53424000	USD
CY2019Q3	us-gaap	Assets Held For Sale Not Part Of Disposal Group AssetsHeldForSaleNotPartOfDisposalGroup	0	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	20541000	USD
CY2019Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	20428000	USD
CY2020Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	0	USD
CY2019Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	6832000	USD
CY2020Q3	nfg	Recoverable Future Taxes RecoverableFutureTaxes	118310000	USD
CY2019Q3	nfg	Recoverable Future Taxes RecoverableFutureTaxes	115197000	USD
CY2020Q3	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	22810000	USD
CY2019Q3	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	25788000	USD
CY2020Q3	us-gaap	Accounts And Other Receivables Net Current AccountsAndOtherReceivablesNetCurrent	143583000	USD
CY2019Q3	us-gaap	Accounts And Other Receivables Net Current AccountsAndOtherReceivablesNetCurrent	139956000	USD
CY2020Q3	us-gaap	Unbilled Receivables Current UnbilledReceivablesCurrent	17302000	USD
CY2019Q3	us-gaap	Unbilled Receivables Current UnbilledReceivablesCurrent	18758000	USD
CY2020Q3	us-gaap	Energy Related Inventory Gas Stored Underground EnergyRelatedInventoryGasStoredUnderground	33338000	USD
CY2019Q3	us-gaap	Energy Related Inventory Gas Stored Underground EnergyRelatedInventoryGasStoredUnderground	36632000	USD
CY2020Q3	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	51877000	USD
CY2019Q3	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	40717000	USD
CY2020Q3	us-gaap	Unrecovered Costs For Purchased Gas Amount UnrecoveredCostsForPurchasedGasAmount	0	USD
CY2019Q3	us-gaap	Unrecovered Costs For Purchased Gas Amount UnrecoveredCostsForPurchasedGasAmount	2246000	USD
CY2020Q3	us-gaap	Other Assets Current OtherAssetsCurrent	47557000	USD
CY2019Q3	us-gaap	Other Assets Current OtherAssetsCurrent	97054000	USD
CY2020Q3	us-gaap	Assets Current AssetsCurrent	314198000	USD
CY2019Q3	us-gaap	Assets Current AssetsCurrent	362623000	USD
CY2020Q3	us-gaap	Unamortized Loss Reacquired Debt Noncurrent UnamortizedLossReacquiredDebtNoncurrent	12297000	USD
CY2019Q3	us-gaap	Other Investments OtherInvestments	144917000	USD
CY2019Q3	us-gaap	Unamortized Loss Reacquired Debt Noncurrent UnamortizedLossReacquiredDebtNoncurrent	14005000	USD
CY2020Q3	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	156106000	USD
CY2019Q3	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	167320000	USD
CY2020Q3	us-gaap	Deferred Costs DeferredCosts	67131000	USD
CY2019Q3	us-gaap	Deferred Costs DeferredCosts	33843000	USD
CY2020Q3	us-gaap	Other Investments OtherInvestments	154502000	USD
CY2020Q3	us-gaap	Goodwill Goodwill	5476000	USD
CY2019Q3	us-gaap	Goodwill Goodwill	5476000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Assets For Plan Benefits Noncurrent DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent	76035000	USD
CY2019Q3	us-gaap	Defined Benefit Plan Assets For Plan Benefits Noncurrent DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent	60517000	USD
CY2020Q3	us-gaap	Derivative Instruments And Hedges Noncurrent DerivativeInstrumentsAndHedgesNoncurrent	9308000	USD
CY2019Q3	us-gaap	Derivative Instruments And Hedges Noncurrent DerivativeInstrumentsAndHedgesNoncurrent	48669000	USD
CY2020Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	81000	USD
CY2019Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	80000	USD
CY2020Q3	nfg	Total Other Assets TotalOtherAssets	599246000	USD
CY2019Q3	nfg	Total Other Assets TotalOtherAssets	590024000	USD
CY2020Q3	us-gaap	Assets Assets	6964935000	USD
CY2019Q3	us-gaap	Assets Assets	6462157000	USD
CY2020Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2019Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2020Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	200000000	shares
CY2019Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	200000000	shares
CY2020Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	90954696	shares
CY2020Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	90954696	shares
CY2019Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	86315287	shares
CY2019Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	86315287	shares
CY2020Q3	us-gaap	Common Stock Value CommonStockValue	90955000	USD
CY2019Q3	us-gaap	Common Stock Value CommonStockValue	86315000	USD
CY2020Q3	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1004158000	USD
CY2019Q3	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	832264000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	991630000	USD
CY2019Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1272601000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-114757000	USD
CY2019Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-52155000	USD
CY2020Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1971986000	USD
CY2019Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	2139025000	USD
CY2020Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2629576000	USD
CY2019Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2133718000	USD
CY2020Q3	us-gaap	Capitalization Longterm Debt And Equity CapitalizationLongtermDebtAndEquity	4601562000	USD
CY2019Q3	us-gaap	Capitalization Longterm Debt And Equity CapitalizationLongtermDebtAndEquity	4272743000	USD
CY2020Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	30000000	USD
CY2019Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	55200000	USD
CY2020Q3	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2019Q3	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2020Q3	us-gaap	Accounts Payable Current AccountsPayableCurrent	134126000	USD
CY2019Q3	us-gaap	Accounts Payable Current AccountsPayableCurrent	132208000	USD
CY2020Q3	us-gaap	Refundable Gas Costs RefundableGasCosts	10788000	USD
CY2019Q3	nfg	Customer Advances CustomerAdvances	13044000	USD
CY2020Q3	us-gaap	Security Deposit Liability SecurityDepositLiability	17199000	USD
CY2019Q3	us-gaap	Refundable Gas Costs RefundableGasCosts	4017000	USD
CY2020Q3	us-gaap	Dividends Payable Current DividendsPayableCurrent	40475000	USD
CY2019Q3	us-gaap	Dividends Payable Current DividendsPayableCurrent	37547000	USD
CY2020Q3	nfg	Interest Payable On Long Term Debt InterestPayableOnLongTermDebt	27521000	USD
CY2019Q3	nfg	Interest Payable On Long Term Debt InterestPayableOnLongTermDebt	18508000	USD
CY2020Q3	nfg	Customer Advances CustomerAdvances	15319000	USD
CY2019Q3	us-gaap	Security Deposit Liability SecurityDepositLiability	16210000	USD
CY2020Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	140176000	USD
CY2019Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	139600000	USD
CY2020Q3	us-gaap	Derivative Instruments And Hedges Liabilities DerivativeInstrumentsAndHedgesLiabilities	43969000	USD
CY2019Q3	us-gaap	Derivative Instruments And Hedges Liabilities DerivativeInstrumentsAndHedgesLiabilities	5574000	USD
CY2020Q3	us-gaap	Liabilities Current LiabilitiesCurrent	459573000	USD
CY2019Q3	us-gaap	Liabilities Current LiabilitiesCurrent	421908000	USD
CY2020Q3	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	696054000	USD
CY2019Q3	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	653382000	USD
CY2019Q3	us-gaap	Deferred Credits And Other Liabilities Noncurrent DeferredCreditsAndOtherLiabilitiesNoncurrent	122368000	USD
CY2020Q3	nfg	Taxes Refundable To Customers TaxesRefundableToCustomers	357508000	USD
CY2019Q3	nfg	Taxes Refundable To Customers TaxesRefundableToCustomers	366503000	USD
CY2020Q3	nfg	Cost Of Removal Regulatory Liability CostOfRemovalRegulatoryLiability	230079000	USD
CY2019Q3	nfg	Cost Of Removal Regulatory Liability CostOfRemovalRegulatoryLiability	221699000	USD
CY2020Q3	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	161573000	USD
CY2019Q3	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	142367000	USD
CY2020Q3	us-gaap	Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent	127181000	USD
CY2019Q3	us-gaap	Pension And Other Postretirement And Postemployment Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesNoncurrent	133729000	USD
CY2020Q3	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	192228000	USD
CY2019Q3	us-gaap	Asset Retirement Obligations Noncurrent AssetRetirementObligationsNoncurrent	127458000	USD
CY2020Q3	us-gaap	Deferred Credits And Other Liabilities Noncurrent DeferredCreditsAndOtherLiabilitiesNoncurrent	139177000	USD
CY2020Q3	us-gaap	Liabilities Noncurrent LiabilitiesNoncurrent	1903800000	USD
CY2019Q3	us-gaap	Liabilities Noncurrent LiabilitiesNoncurrent	1767506000	USD
CY2020Q3	us-gaap	Commitments And Contingencies CommitmentsAndContingencies	0	USD
CY2019Q3	us-gaap	Commitments And Contingencies CommitmentsAndContingencies	0	USD
CY2020Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	6964935000	USD
CY2019Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	6462157000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-123772000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	304290000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	391521000	USD
CY2020	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	449438000	USD
CY2019	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	0	USD
CY2018	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	0	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	306158000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	275660000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	240961000	USD
CY2020	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	54313000	USD
CY2019	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	122265000	USD
CY2018	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	-18153000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	14931000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	21186000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	15762000	USD
CY2020	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-6527000	USD
CY2019	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-8608000	USD
CY2018	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-16133000	USD
CY2020	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	2578000	USD
CY2019	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-6379000	USD
CY2018	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	30882000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	6625000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	3713000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	4021000	USD
CY2020	us-gaap	Increase Decrease In Deferred Gas Cost IncreaseDecreaseInDeferredGasCost	-2246000	USD
CY2019	us-gaap	Increase Decrease In Deferred Gas Cost IncreaseDecreaseInDeferredGasCost	-1958000	USD
CY2018	us-gaap	Increase Decrease In Deferred Gas Cost IncreaseDecreaseInDeferredGasCost	-419000	USD
CY2020	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-49367000	USD
CY2019	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	29030000	USD
CY2018	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	16519000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	-4657000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	-24770000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	17962000	USD
CY2020	us-gaap	Increase Decrease In Regulatory Clause Revenue IncreaseDecreaseInRegulatoryClauseRevenue	6771000	USD
CY2019	us-gaap	Increase Decrease In Regulatory Clause Revenue IncreaseDecreaseInRegulatoryClauseRevenue	623000	USD
CY2018	us-gaap	Increase Decrease In Regulatory Clause Revenue IncreaseDecreaseInRegulatoryClauseRevenue	3394000	USD
CY2020	nfg	Increase Decrease In Customer Advances Current IncreaseDecreaseInCustomerAdvancesCurrent	2275000	USD
CY2019	nfg	Increase Decrease In Customer Advances Current IncreaseDecreaseInCustomerAdvancesCurrent	-565000	USD
CY2018	nfg	Increase Decrease In Customer Advances Current IncreaseDecreaseInCustomerAdvancesCurrent	-2092000	USD
CY2020	us-gaap	Increase Decrease In Security Deposits IncreaseDecreaseInSecurityDeposits	989000	USD
CY2019	us-gaap	Increase Decrease In Security Deposits IncreaseDecreaseInSecurityDeposits	-9493000	USD
CY2018	us-gaap	Increase Decrease In Security Deposits IncreaseDecreaseInSecurityDeposits	5331000	USD
CY2020	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	5001000	USD
CY2019	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	10992000	USD
CY2018	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	3865000	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	24203000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	-5115000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	615303000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	716153000	USD
CY2018	us-gaap	Proceeds From Sale Of Oil And Gas Property And Equipment ProceedsFromSaleOfOilAndGasPropertyAndEquipment	55506000	USD
CY2018	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	9556000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	4628000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	4978000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	1178000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	740809000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	694483000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	788938000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	584004000	USD
CY2020	nfg	Acquisition Of Upstream Assets And Midstream Gathering Assets AcquisitionOfUpstreamAssetsAndMidstreamGatheringAssets	506258000	USD
CY2019	nfg	Acquisition Of Upstream Assets And Midstream Gathering Assets AcquisitionOfUpstreamAssetsAndMidstreamGatheringAssets	0	USD
CY2018	nfg	Acquisition Of Upstream Assets And Midstream Gathering Assets AcquisitionOfUpstreamAssetsAndMidstreamGatheringAssets	0	USD
CY2020	us-gaap	Proceeds From Sale Of Oil And Gas Property And Equipment ProceedsFromSaleOfOilAndGasPropertyAndEquipment	0	USD
CY2019	us-gaap	Proceeds From Sale Of Oil And Gas Property And Equipment ProceedsFromSaleOfOilAndGasPropertyAndEquipment	0	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	1205000	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	10237000	USD
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	389000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1223616000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-799175000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-528887000	USD
CY2020	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-25200000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	55200000	USD
CY2018	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	0	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	493007000	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	295020000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	0	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	0	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	566512000	USD
CY2020	us-gaap	Proceeds From Issuance Or Sale Of Equity ProceedsFromIssuanceOrSaleOfEquity	161603000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	102920000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-410640000	USD
CY2019	us-gaap	Payments For Repurchase Of Equity PaymentsForRepurchaseOfEquity	8877000	USD
CY2018	us-gaap	Proceeds From Issuance Or Sale Of Equity ProceedsFromIssuanceOrSaleOfEquity	4110000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	153322000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	147418000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	143258000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	476088000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-101095000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-6719000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-205787000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	-324224000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	27260000	USD
CY2018Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	233047000	USD
CY2017Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	557271000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	20541000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	27260000	USD
CY2018Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	233047000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	103479000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	126079000	USD
CY2020	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	82876000	USD
CY2019	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	17342000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	31771000	USD
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	87328000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	81121000	USD
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	88813000	USD
CY2020Q3	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	1800000000	USD
CY2019Q3	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	1700000000	USD
CY2020Q3	nfg	Full Cost Ceiling Test Discount Factor FullCostCeilingTestDiscountFactor	0.10
CY2020	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	449400000	USD
CY2020	us-gaap	Effect On Future Cash Flows Amount EffectOnFutureCashFlowsAmount	180000000.0	USD
CY2019	us-gaap	Effect On Future Cash Flows Amount EffectOnFutureCashFlowsAmount	-17700000	USD
CY2018	us-gaap	Effect On Future Cash Flows Amount EffectOnFutureCashFlowsAmount	-25100000	USD
CY2020	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	166800000	USD
CY2019	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	149900000	USD
CY2018	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	119900000	USD
CY2020Q3	nfg	Depreciable Plant Assets DepreciablePlantAssets	11906360000	USD
CY2019Q3	nfg	Depreciable Plant Assets DepreciablePlantAssets	10788616000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit After Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax	900000	USD
CY2020Q3	us-gaap	Goodwill Goodwill	5500000	USD
CY2019Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-52155000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-7573000	USD
CY2020	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	55979000	USD
CY2020	nfg	Cumulative Effectof Adoptionof Authoritative Guidancefor Hedging CumulativeEffectofAdoptionofAuthoritativeGuidanceforHedging	950000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-114757000	USD
CY2018Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-67750000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	25066000	USD
CY2019	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-8372000	USD
CY2019	nfg	Reclassification Adjustmentfrom Aoc Ifor Cumulative Effectof Adoptionof Authoritative Guidancefor Financial Assetsand Liabilities ReclassificationAdjustmentfromAOCIforCumulativeEffectofAdoptionofAuthoritativeGuidanceforFinancialAssetsandLiabilities	7437000	USD
CY2019	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	-10406000	USD
CY2019Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-52155000	USD
CY2019Q3	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit After Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax	1000000.0	USD
CY2020Q3	nfg	Materials And Supplies At Average Cost MaterialsAndSuppliesAtAverageCost	33859000	USD
CY2019Q3	nfg	Materials And Supplies At Average Cost MaterialsAndSuppliesAtAverageCost	29819000	USD
CY2020Q3	nfg	Emission Allowances EmissionAllowances	18018000	USD
CY2019Q3	nfg	Emission Allowances EmissionAllowances	10898000	USD
CY2020Q3	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	51877000	USD
CY2019Q3	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	40717000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	20541000	USD
CY2019Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	20428000	USD
CY2018Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	229606000	USD
CY2017Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	555530000	USD
CY2020Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	0	USD
CY2019Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	6832000	USD
CY2018Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	3441000	USD
CY2017Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	1741000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	20541000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	27260000	USD
CY2018Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	233047000	USD
CY2017Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	557271000	USD
CY2020Q3	us-gaap	Other Prepaid Expense Current OtherPrepaidExpenseCurrent	12851000	USD
CY2019Q3	us-gaap	Other Prepaid Expense Current OtherPrepaidExpenseCurrent	12728000	USD
CY2020Q3	us-gaap	Prepaid Taxes PrepaidTaxes	14269000	USD
CY2019Q3	us-gaap	Prepaid Taxes PrepaidTaxes	14361000	USD
CY2020Q3	nfg	Other Current Assets Fair Values Of Firm Commitments OtherCurrentAssetsFairValuesOfFirmCommitments	0	USD
CY2019Q3	nfg	Other Current Assets Fair Values Of Firm Commitments OtherCurrentAssetsFairValuesOfFirmCommitments	7538000	USD
CY2020Q3	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	16609000	USD
CY2019Q3	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	11460000	USD
CY2020Q3	us-gaap	Other Assets Current OtherAssetsCurrent	47557000	USD
CY2019Q3	us-gaap	Other Assets Current OtherAssetsCurrent	97054000	USD
CY2020Q3	nfg	Liabilityfor Royaltyand Working Interest Current LiabilityforRoyaltyandWorkingInterestCurrent	15665000	USD
CY2019Q3	nfg	Liabilityfor Royaltyand Working Interest Current LiabilityforRoyaltyandWorkingInterestCurrent	18057000	USD
CY2020Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	140176000	USD
CY2019Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	139600000	USD
CY2020Q3	nfg	Customer Advances CustomerAdvances	15300000	USD
CY2019Q3	nfg	Customer Advances CustomerAdvances	13000000.0	USD
CY2020Q3	us-gaap	Security Deposit Liability SecurityDepositLiability	17200000	USD
CY2019Q3	us-gaap	Security Deposit Liability SecurityDepositLiability	16200000	USD
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	411890	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	242302	shares
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	317899	shares
CY2020Q3	nfg	Asset Acquisition Consideration Transferred AssetAcquisitionConsiderationTransferred	506300000	USD
CY2020Q3	nfg	Net Acres Acquired In Appalachia NetAcresAcquiredInAppalachia	400000	acre
CY2020Q3	nfg	Net Acres Acquired In Tioga County NetAcresAcquiredInTiogaCounty	200000	acre
CY2020	srt	Proved Developed And Undeveloped Reserves Purchases Of Minerals In Place ProvedDevelopedAndUndevelopedReservesPurchasesOfMineralsInPlace	684141	Bcf
CY2020Q3	nfg	Purchase Price To Acquire Upstream Assets And Midstream Gathering Assets PurchasePriceToAcquireUpstreamAssetsAndMidstreamGatheringAssets	503908000	USD
CY2020Q3	nfg	Asset Acquisition Transaction Costs AssetAcquisitionTransactionCosts	2350000	USD
CY2020Q3	nfg	Asset Acquisition Consideration Transferred AssetAcquisitionConsiderationTransferred	506258000	USD
CY2020Q3	nfg	Asset Acquisition Inventory AssetAcquisitionInventory	1241000	USD
CY2020Q3	nfg	Asset Acquisition Assets AssetAcquisitionAssets	506258000	USD
CY2020Q3	nfg	Anticipated Proceeds From Sale Of Certain Timber And Other Assets AnticipatedProceedsFromSaleOfCertainTimberAndOtherAssets	115700000	USD
CY2020Q3	us-gaap	Assets Held For Sale Not Part Of Disposal Group AssetsHeldForSaleNotPartOfDisposalGroup	53400000	USD
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	185200000	USD
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	163700000	USD
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	132400000	USD
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	123000000.0	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	0	USD
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	116700000	USD
CY2020Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	517400000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	4129000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	525000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	918000	USD
CY2020	us-gaap	Sublease Income SubleaseIncome	297000	USD
CY2020	us-gaap	Lease Cost LeaseCost	5275000	USD
CY2020Q3	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y4M24D
CY2020Q3	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0339
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	5300000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	12356000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	2813000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	4968000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	3045000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	2507000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	2238000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	2086000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	7631000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	22475000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	2755000	USD
CY2017Q3	us-gaap	Asset Retirement Obligation AssetRetirementObligation	106395000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	2264000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	2270000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	2237000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	9717000	USD
CY2019Q3	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	31657000	USD
CY2019Q3	us-gaap	Asset Retirement Obligation AssetRetirementObligation	127458000	USD
CY2018Q3	us-gaap	Asset Retirement Obligation AssetRetirementObligation	108235000	USD
CY2020	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	61246000	USD
CY2019	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	4122000	USD
CY2018	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	5597000	USD
CY2020	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	3267000	USD
CY2019	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	16693000	USD
CY2018	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	-419000	USD
CY2020	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	7268000	USD
CY2019	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	7670000	USD
CY2018	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	12858000	USD
CY2020	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	7525000	USD
CY2019	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	6078000	USD
CY2018	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	9520000	USD
CY2020Q3	us-gaap	Asset Retirement Obligation AssetRetirementObligation	192228000	USD
CY2019Q3	us-gaap	Asset Retirement Obligation AssetRetirementObligation	127458000	USD
CY2018Q3	us-gaap	Asset Retirement Obligation AssetRetirementObligation	108235000	USD
CY2020Q3	us-gaap	Regulatory Assets RegulatoryAssets	303322000	USD
CY2019Q3	us-gaap	Regulatory Assets RegulatoryAssets	307982000	USD
CY2020Q3	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	16609000	USD
CY2019Q3	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	11460000	USD
CY2020Q3	us-gaap	Regulatory Liabilities RegulatoryLiabilities	804838000	USD
CY2019Q3	us-gaap	Regulatory Liabilities RegulatoryLiabilities	784918000	USD
CY2020Q3	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	55678000	USD
CY2019Q3	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	54349000	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.245
CY2020Q3	nfg	First Installment Of Amt Credit Refunds FirstInstallmentOfAMTCreditRefunds	42500000	USD
CY2020Q3	nfg	Accelerated Amt Credit Refund Received Under Cares Act AcceleratedAMTCreditRefundReceivedUnderCARESAct	42500000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-42548000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-41645000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	2025000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	6974000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	4601000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	4538000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	8634000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	98514000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-38927000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	49775000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	23751000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	20774000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18739000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85221000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-7494000	USD
CY2020	us-gaap	Investment Tax Credit InvestmentTaxCredit	13000	USD
CY2019	us-gaap	Investment Tax Credit InvestmentTaxCredit	91000	USD
CY2018	us-gaap	Investment Tax Credit InvestmentTaxCredit	105000	USD
CY2020	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	18726000	USD
CY2019	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	85130000	USD
CY2018	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	-7599000	USD
CY2018	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	6576000	USD
CY2020	us-gaap	Investment Tax Credit InvestmentTaxCredit	13000	USD
CY2020	nfg	Income From Continuing Operations Before Income Taxes IncomeFromContinuingOperationsBeforeIncomeTaxes	-105046000	USD
CY2019	nfg	Income From Continuing Operations Before Income Taxes IncomeFromContinuingOperationsBeforeIncomeTaxes	389420000	USD
CY2018	nfg	Income From Continuing Operations Before Income Taxes IncomeFromContinuingOperationsBeforeIncomeTaxes	383922000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-22060000	USD
CY2019	us-gaap	Investment Tax Credit InvestmentTaxCredit	91000	USD
CY2018	us-gaap	Investment Tax Credit InvestmentTaxCredit	105000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18739000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85221000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-7494000	USD
CY2020	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	18726000	USD
CY2019	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	85130000	USD
CY2018	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	-7599000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	81778000	USD
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	94061000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	63205000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	USD
CY2018	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	0	USD
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	-18374000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	22397000	USD
CY2018	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	22203000	USD
CY2020	nfg	Effective Income Tax Rate Reconciliation Deductible Expense Amortizationof Excess Deferred Income Taxes EffectiveIncomeTaxRateReconciliationDeductibleExpenseAmortizationofExcessDeferredIncomeTaxes	-4749000	USD
CY2019	nfg	Effective Income Tax Rate Reconciliation Deductible Expense Amortizationof Excess Deferred Income Taxes EffectiveIncomeTaxRateReconciliationDeductibleExpenseAmortizationofExcessDeferredIncomeTaxes	-3185000	USD
CY2018	nfg	Effective Income Tax Rate Reconciliation Deductible Expense Amortizationof Excess Deferred Income Taxes EffectiveIncomeTaxRateReconciliationDeductibleExpenseAmortizationofExcessDeferredIncomeTaxes	-1336000	USD
CY2020	nfg	Effective Income Tax Rate Reconciliation Plant Flow Through Items EffectiveIncomeTaxRateReconciliationPlantFlowThroughItems	-2848000	USD
CY2019	nfg	Effective Income Tax Rate Reconciliation Plant Flow Through Items EffectiveIncomeTaxRateReconciliationPlantFlowThroughItems	-1544000	USD
CY2018	nfg	Effective Income Tax Rate Reconciliation Plant Flow Through Items EffectiveIncomeTaxRateReconciliationPlantFlowThroughItems	-872000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	3867000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-1491000	USD
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-321000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	217000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	7361000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	0	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	-5000000	USD
CY2018	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	-112598000	USD
CY2020	us-gaap	Income Tax Reconciliation Deductions Other IncomeTaxReconciliationDeductionsOther	98000	USD
CY2019	us-gaap	Income Tax Reconciliation Deductions Other IncomeTaxReconciliationDeductionsOther	464000	USD
CY2018	us-gaap	Income Tax Reconciliation Deductions Other IncomeTaxReconciliationDeductionsOther	2160000	USD
CY2020	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	18726000	USD
CY2019	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	85130000	USD
CY2018	nfg	Income Tax Expense Benefit Including Deferred Investment Tax Credit IncomeTaxExpenseBenefitIncludingDeferredInvestmentTaxCredit	-7599000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.245
CY2017Q4	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2019	nfg	Reversalof Estimate For Potential Sequestrationof Amt Credit Refunds Under2017 Tax Reform Ac ReversalofEstimateForPotentialSequestrationofAMTCreditRefundsUnder2017TaxReformAc	5000000.0	USD
CY2018	nfg	Estimate For Potential Sequestrationof Amt Credit Refunds Under2017 Tax Reform Act EstimateForPotentialSequestrationofAMTCreditRefundsUnder2017TaxReformAct	5000000.0	USD
CY2018	nfg	Income Tax Benefitfrom Blended Tax Rateunder2017 Tax Reform Act IncomeTaxBenefitfromBlendedTaxRateunder2017TaxReformAct	9100000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	44239000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	874607000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	861278000	USD
CY2020Q3	nfg	Deferred Tax Liabilities Pension And Other Post Retirement Costs DeferredTaxLiabilitiesPensionAndOtherPostRetirementCosts	54066000	USD
CY2019Q3	nfg	Deferred Tax Liabilities Pension And Other Post Retirement Costs DeferredTaxLiabilitiesPensionAndOtherPostRetirementCosts	55795000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	23377000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	54486000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	952050000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	971559000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Capital Loss Carryforwards DeferredTaxAssetsCapitalLossCarryforwards	179363000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Capital Loss Carryforwards DeferredTaxAssetsCapitalLossCarryforwards	175542000	USD
CY2020Q3	nfg	Deferred Tax Assets Pension And Other Post Retirement Costs DeferredTaxAssetsPensionAndOtherPostRetirementCosts	95599000	USD
CY2019Q3	nfg	Deferred Tax Assets Pension And Other Post Retirement Costs DeferredTaxAssetsPensionAndOtherPostRetirementCosts	87280000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	55355000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	319201000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	318177000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	63205000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	USD
CY2020Q3	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	255996000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	318177000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	696054000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	653382000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	56800000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	63200000	USD
CY2019Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2018Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2017Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1251000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	788000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	463000	USD
CY2020Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2019Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2018Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2020Q3	us-gaap	Deferred Tax Assets Charitable Contribution Carryforwards DeferredTaxAssetsCharitableContributionCarryforwards	1559000	USD
CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.68
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.72
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.76
CY2020Q3	nfg	Earnings Reinvested In Business Available For Dividends EarningsReinvestedInBusinessAvailableForDividends	848400000	USD
CY2020	us-gaap	Stock Issued During Period Shares Dividend Reinvestment Plan StockIssuedDuringPeriodSharesDividendReinvestmentPlan	0	shares
CY2020	us-gaap	Stock Issued During Period Shares Employee Benefit Plan StockIssuedDuringPeriodSharesEmployeeBenefitPlan	0	shares
CY2020	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	91545	shares
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13100000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	19500000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	14200000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	2100000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3800000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3400000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	100000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	100000	USD
CY2020Q3	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	1
CY2018	us-gaap	Employee Service Share Based Compensation Allocation Of Recognized Period Costs Capitalized Amount EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount	100000	USD
CY2020	nfg	Employee Service Share Based Compensation Tax Expense From Exercises Vestings Stock Based Compensation EmployeeServiceShareBasedCompensationTaxExpenseFromExercisesVestingsStockBasedCompensation	3200000	USD
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	3220528	shares
CY2020Q3	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	10000000	shares
CY2020Q3	us-gaap	Unsecured Debt UnsecuredDebt	2649000000	USD
CY2019Q3	us-gaap	Unsecured Debt UnsecuredDebt	2149000000	USD
CY2020Q3	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	19424000	USD
CY2019Q3	us-gaap	Debt Instrument Unamortized Discount Premium And Debt Issuance Costs Net DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet	15282000	USD
CY2020Q3	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2019Q3	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2020Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2629576000	USD
CY2019Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	2133718000	USD
CY2018	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	1000000.0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	500000000.0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	549000000.0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	500000000.0	USD
CY2020Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	1100000000.0	USD
CY2020Q3	us-gaap	Short Term Bank Loans And Notes Payable ShortTermBankLoansAndNotesPayable	15000000.0	USD
CY2020Q3	us-gaap	Commercial Paper At Carrying Value CommercialPaperAtCarryingValue	15000000.0	USD
CY2019Q3	us-gaap	Commercial Paper At Carrying Value CommercialPaperAtCarryingValue	55200000	USD
CY2020Q3	nfg	Fair Value Liabilities Measured On Recurring Basis Total FairValueLiabilitiesMeasuredOnRecurringBasisTotal	43969000	USD
CY2020Q3	nfg	Fair Value Assets Liabilities Measured On Recurring Basis Net FairValueAssetsLiabilitiesMeasuredOnRecurringBasisNet	90045000	USD
CY2020	nfg	Committed Credit Facility Debt To Capitalization Ratio CommittedCreditFacilityDebtToCapitalizationRatio	0.65
CY2020Q3	nfg	Committed Credit Facility Debtto Capitalization Ratio Ceiling Test Impairment Adjustment CommittedCreditFacilityDebttoCapitalizationRatioCeilingTestImpairmentAdjustment	0.50
CY2020Q3	nfg	Committed Credit Facility Debtto Capitalization Ratio Ceiling Test Impairment Maximum Adjustment CommittedCreditFacilityDebttoCapitalizationRatioCeilingTestImpairmentMaximumAdjustment	250000000	USD
CY2020	nfg	Cumulative Impairment Of Oil And Gas Producing Properties After Tax CumulativeImpairmentOfOilAndGasProducingPropertiesAfterTax	326300000	USD
CY2020Q3	nfg	Committed Credit Facility Debt To Capitalization Ratio Ceiling Test Impairment Adjustment Amount CommittedCreditFacilityDebtToCapitalizationRatioCeilingTestImpairmentAdjustmentAmount	163100000	USD
CY2020	nfg	Debt To Capitalization Ratio DebtToCapitalizationRatio	0.55
CY2020Q3	us-gaap	Debt Instrument Unused Borrowing Capacity Amount DebtInstrumentUnusedBorrowingCapacityAmount	1300000000	USD
CY2020	nfg	Committed Credit Facility Debt To Capitalization Ratio CommittedCreditFacilityDebtToCapitalizationRatio	0.65
CY2020	nfg	Amount Which Could Trigger Repayment Obligation Under Committed Credit Facility AmountWhichCouldTriggerRepaymentObligationUnderCommittedCreditFacility	40000000.0	USD
CY2020	nfg	Amount Which Could Trigger Repayment Obligation Under Committed Credit Facility AmountWhichCouldTriggerRepaymentObligationUnderCommittedCreditFacility	40000000.0	USD
CY2020	nfg	Debt Instrument Principal Outstanding Portion Of Long Term Debt DebtInstrumentPrincipalOutstandingPortionOfLongTermDebt	0.037
CY2020Q3	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	12285000	USD
CY2020Q3	nfg	Fair Value Assets Measured On Recurring Basis Total FairValueAssetsMeasuredOnRecurringBasisTotal	134014000	USD
CY2019Q3	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	10521000	USD
CY2019Q3	nfg	Fair Value Assets Measured On Recurring Basis Total FairValueAssetsMeasuredOnRecurringBasisTotal	169742000	USD
CY2019Q3	us-gaap	Margin Deposit Assets MarginDepositAssets	6832000	USD
CY2019Q3	nfg	Fair Value Liabilities Measured On Recurring Basis Total FairValueLiabilitiesMeasuredOnRecurringBasisTotal	5574000	USD
CY2019Q3	nfg	Fair Value Assets Liabilities Measured On Recurring Basis Net FairValueAssetsLiabilitiesMeasuredOnRecurringBasisNet	164168000	USD
CY2020Q3	us-gaap	Long Term Debt LongTermDebt	2629576000	USD
CY2020Q3	us-gaap	Debt Instrument Fair Value DebtInstrumentFairValue	2778556000	USD
CY2019Q3	us-gaap	Long Term Debt LongTermDebt	2133718000	USD
CY2019Q3	us-gaap	Debt Instrument Fair Value DebtInstrumentFairValue	2257085000	USD
CY2020Q3	us-gaap	Cash Surrender Value Of Life Insurance CashSurrenderValueOfLifeInsurance	41992000	USD
CY2019Q3	us-gaap	Cash Surrender Value Of Life Insurance CashSurrenderValueOfLifeInsurance	41074000	USD
CY2020Q3	us-gaap	Other Investments OtherInvestments	154502000	USD
CY2019Q3	us-gaap	Other Investments OtherInvestments	144917000	USD
CY2020	us-gaap	Maximum Remaining Maturity Of Foreign Currency Derivatives1 MaximumRemainingMaturityOfForeignCurrencyDerivatives1	P10Y
CY2019	us-gaap	Derivative Instruments Gain Loss Recognized In Income Ineffective Portion And Amount Excluded From Effectiveness Testing Net DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet	2100000	USD
CY2020Q3	nfg	Net Hedging Gains Losses In Accumulated Other Comprehensive Income Loss NetHedgingGainsLossesInAccumulatedOtherComprehensiveIncomeLoss	34800000	USD
CY2020Q3	us-gaap	Aoci Loss Cash Flow Hedge Cumulative Gain Loss After Tax AociLossCashFlowHedgeCumulativeGainLossAfterTax	24900000	USD
CY2020	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	26700000	USD
CY2020	nfg	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months After Tax CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonthsAfterTax	19100000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	9862000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	79301000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax	93295000	USD
CY2019	us-gaap	Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet	-5464000	USD
CY2020Q3	us-gaap	Credit Risk Derivative Assets At Fair Value CreditRiskDerivativeAssetsAtFairValue	8600000	USD
CY2020Q3	us-gaap	Credit Risk Derivative Liabilities At Fair Value CreditRiskDerivativeLiabilitiesAtFairValue	44000000.0	USD
CY2020	nfg	Amortization Period AmortizationPeriod	P10Y
CY2020	nfg	Estimated Gross Other Post Retirement Benefit Payments Rate Of Increase For Pre Age Sixty Five Participants EstimatedGrossOtherPostRetirementBenefitPaymentsRateOfIncreaseForPreAgeSixtyFiveParticipants	0.0542
CY2019	nfg	Estimated Gross Other Post Retirement Benefit Payments Rate Of Increase For Pre Age Sixty Five Participants EstimatedGrossOtherPostRetirementBenefitPaymentsRateOfIncreaseForPreAgeSixtyFiveParticipants	0.0550
CY2018	nfg	Estimated Gross Other Post Retirement Benefit Payments Rate Of Increase For Pre Age Sixty Five Participants EstimatedGrossOtherPostRetirementBenefitPaymentsRateOfIncreaseForPreAgeSixtyFiveParticipants	0.0559
CY2020	nfg	Estimated Gross Other Post Retirement Benefit Payments Rate Of Increase For Post Age Sixty Five Participants EstimatedGrossOtherPostRetirementBenefitPaymentsRateOfIncreaseForPostAgeSixtyFiveParticipants	0.0475
CY2019	nfg	Estimated Gross Other Post Retirement Benefit Payments Rate Of Increase For Post Age Sixty Five Participants EstimatedGrossOtherPostRetirementBenefitPaymentsRateOfIncreaseForPostAgeSixtyFiveParticipants	0.0475
CY2018	nfg	Estimated Gross Other Post Retirement Benefit Payments Rate Of Increase For Post Age Sixty Five Participants EstimatedGrossOtherPostRetirementBenefitPaymentsRateOfIncreaseForPostAgeSixtyFiveParticipants	0.0475
CY2020	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Cost Of Covered Prescription Drug Benefits EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaCostOfCoveredPrescriptionDrugBenefits	0.0680
CY2019	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Cost Of Covered Prescription Drug Benefits EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaCostOfCoveredPrescriptionDrugBenefits	0.0735
CY2018	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Cost Of Covered Prescription Drug Benefits EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaCostOfCoveredPrescriptionDrugBenefits	0.0789
CY2020	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Medicare Part B Reimbursement EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaMedicarePartBReimbursement	0.0475
CY2019	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Medicare Part B Reimbursement EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaMedicarePartBReimbursement	0.0475
CY2018	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Medicare Part B Reimbursement EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaMedicarePartBReimbursement	0.0475
CY2020	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Medicare Part D Subsidy EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaMedicarePartDSubsidy	0.0620
CY2019	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Medicare Part D Subsidy EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaMedicarePartDSubsidy	0.0684
CY2018	nfg	Estimated Gross Other Post Retirement Benefit Payments Annual Rate Of Increase In Per Capita Medicare Part D Subsidy EstimatedGrossOtherPostRetirementBenefitPaymentsAnnualRateOfIncreaseInPerCapitaMedicarePartDSubsidy	0.0718
CY2019Q3	us-gaap	Defined Benefit Plan Ultimate Health Care Cost Trend Rate1 DefinedBenefitPlanUltimateHealthCareCostTrendRate1	0.045
CY2018Q3	us-gaap	Defined Benefit Plan Ultimate Health Care Cost Trend Rate1 DefinedBenefitPlanUltimateHealthCareCostTrendRate1	0.045
CY2020Q3	us-gaap	Defined Benefit Plan Ultimate Health Care Cost Trend Rate1 DefinedBenefitPlanUltimateHealthCareCostTrendRate1	0.045
CY2020	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Increase On Accumulated Postretirement Benefit Obligation DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation	61700000	USD
CY2020	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Increase On Service And Interest Cost Components DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents	2500000	USD
CY2020	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Decrease On Accumulated Postretirement Benefit Obligation1 DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1	51500000	USD
CY2020	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Decrease On Service And Interest Cost Components1 DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1	1800000	USD
CY2019Q3	us-gaap	Fair Value Assets Level1 To Level2 Transfers Amount FairValueAssetsLevel1ToLevel2TransfersAmount	0	USD
CY2020Q3	us-gaap	Fair Value Assets Level1 To Level2 Transfers Amount FairValueAssetsLevel1ToLevel2TransfersAmount	0	USD
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Net FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet	0	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Net FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet	0	USD
CY2020Q3	us-gaap	Loss Contingency Estimate Of Possible Loss LossContingencyEstimateOfPossibleLoss	6400000	USD
CY2020Q3	us-gaap	Recorded Unconditional Purchase Obligation Due Within One Year RecordedUnconditionalPurchaseObligationDueWithinOneYear	181900000	USD
CY2020Q3	us-gaap	Recorded Unconditional Purchase Obligation Due In Second Year RecordedUnconditionalPurchaseObligationDueInSecondYear	111300000	USD
CY2020Q3	us-gaap	Recorded Unconditional Purchase Obligation Due In Third Year RecordedUnconditionalPurchaseObligationDueInThirdYear	120900000	USD
CY2020Q3	us-gaap	Recorded Unconditional Purchase Obligation Due In Fourth Year RecordedUnconditionalPurchaseObligationDueInFourthYear	129300000	USD
CY2020Q3	us-gaap	Recorded Unconditional Purchase Obligation Due In Fifth Year RecordedUnconditionalPurchaseObligationDueInFifthYear	146300000	USD
CY2020Q3	us-gaap	Recorded Unconditional Purchase Obligation Due After Fifth Year RecordedUnconditionalPurchaseObligationDueAfterFifthYear	1128200000	USD
CY2020	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	4	segment
CY2020	us-gaap	Interest Income Domestic Deposits InterestIncomeDomesticDeposits	5007000	USD
CY2020	us-gaap	Interest Expense InterestExpense	117077000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	306158000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18739000	USD
CY2020	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	449438000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-123772000	USD
CY2020	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	1228617000	USD
CY2020Q3	us-gaap	Assets Assets	6964935000	USD
CY2019	us-gaap	Interest Expense InterestExpense	106756000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	86591000	USD
CY2019	us-gaap	Interest Income Domestic Deposits InterestIncomeDomesticDeposits	6065000	USD
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.00
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	275660000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85221000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	304290000	USD
CY2019	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	781246000	USD
CY2019Q3	us-gaap	Assets Assets	6462157000	USD
CY2018	us-gaap	Interest Income Domestic Deposits InterestIncomeDomesticDeposits	6766000	USD
CY2018	us-gaap	Interest Expense InterestExpense	114522000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	240961000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-7494000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	391521000	USD
CY2018	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	600602000	USD
CY2018Q3	us-gaap	Assets Assets	6036486000	USD
CY2020Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	-173979000	USD
CY2020Q3	us-gaap	Revenues Revenues	287989000	USD
CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	148020000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	-145545000	USD
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-1.60
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.60
CY2020Q2	us-gaap	Revenues Revenues	323019000	USD
CY2020Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	80397000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	41250000	USD
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.47
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.47
CY2020Q1	us-gaap	Revenues Revenues	491095000	USD
CY2020Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	-24580000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	-106068000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-1.23
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-1.23
CY2019Q4	us-gaap	Revenues Revenues	444188000	USD
CY2018Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	161683000	USD
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.00
CY2019Q3	us-gaap	Revenues Revenues	293341000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	83940000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	47282000	USD
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.55
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.54
CY2019Q2	us-gaap	Revenues Revenues	357200000	USD
CY2019Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	112827000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	63753000	USD
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.74
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.73
CY2019Q1	us-gaap	Revenues Revenues	552544000	USD
CY2019Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	153359000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	90595000	USD
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.05
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.04
CY2020	us-gaap	Development Costs DevelopmentCosts	54761000	USD
CY2018Q4	us-gaap	Revenues Revenues	490247000	USD
CY2018Q4	us-gaap	Net Income Loss NetIncomeLoss	102660000	USD
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.19
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.18
CY2020Q3	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	253400000	USD
CY2020Q3	nfg	Impairment Of Oil And Gas Producing Properties After Tax ImpairmentOfOilAndGasProducingPropertiesAfterTax	183700000	USD
CY2020Q2	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	18200000	USD
CY2020Q2	nfg	Impairment Of Oil And Gas Producing Properties After Tax ImpairmentOfOilAndGasProducingPropertiesAfterTax	13300000	USD
CY2020Q1	nfg	Impairmentof Oiland Gas Producing Properties ImpairmentofOilandGasProducingProperties	177800000	USD
CY2020Q1	nfg	Impairment Of Oil And Gas Producing Properties After Tax ImpairmentOfOilAndGasProducingPropertiesAfterTax	129300000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	56800000	USD
CY2018Q4	us-gaap	Income Tax Expense Benefit Continuing Operations Adjustment Of Deferred Tax Asset Liability IncomeTaxExpenseBenefitContinuingOperationsAdjustmentOfDeferredTaxAssetLiability	-5000000.0	USD
CY2020Q3	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	6238830000	USD
CY2018	us-gaap	Acquisition Costs AcquisitionCosts	0	USD
CY2019Q3	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	5623623000	USD
CY2020Q3	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	148075000	USD
CY2019Q3	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	53498000	USD
CY2020Q3	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	6386905000	USD
CY2019Q3	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	5677121000	USD
CY2020Q3	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	4628765000	USD
CY2019Q3	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	4012568000	USD
CY2020Q3	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	1758140000	USD
CY2019Q3	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	1664553000	USD
CY2020Q3	us-gaap	Capitalized Costs Asset Retirement Costs CapitalizedCostsAssetRetirementCosts	132600000	USD
CY2019Q3	us-gaap	Capitalized Costs Asset Retirement Costs CapitalizedCostsAssetRetirementCosts	70500000	USD
CY2020	us-gaap	Acquisition Costs AcquisitionCosts	39953000	USD
CY2019	us-gaap	Acquisition Costs AcquisitionCosts	0	USD
CY2019	us-gaap	Development Costs DevelopmentCosts	17326000	USD
CY2018	us-gaap	Development Costs DevelopmentCosts	403000	USD
CY2020	us-gaap	Exploration Costs ExplorationCosts	0	USD
CY2019	us-gaap	Exploration Costs ExplorationCosts	0	USD
CY2018	us-gaap	Exploration Costs ExplorationCosts	0	USD
CY2020	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	969000	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	41000	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	0	USD
CY2020	us-gaap	Capitalized Costs Of Unproved Properties Excluded From Amortization CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization	95683000	USD
CY2019	us-gaap	Capitalized Costs Of Unproved Properties Excluded From Amortization CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization	17367000	USD
CY2018	us-gaap	Capitalized Costs Of Unproved Properties Excluded From Amortization CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization	403000	USD
CY2020	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties With Proved Reserves CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves	245976000	USD
CY2019	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties With Proved Reserves CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves	3136000	USD
CY2018	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties With Proved Reserves CostsIncurredAcquisitionOfOilAndGasPropertiesWithProvedReserves	1544000	USD
CY2020	us-gaap	Costs Incurred Acquisition Of Unproved Oil And Gas Properties CostsIncurredAcquisitionOfUnprovedOilAndGasProperties	42922000	USD
CY2019	us-gaap	Costs Incurred Acquisition Of Unproved Oil And Gas Properties CostsIncurredAcquisitionOfUnprovedOilAndGasProperties	3679000	USD
CY2018	us-gaap	Costs Incurred Acquisition Of Unproved Oil And Gas Properties CostsIncurredAcquisitionOfUnprovedOilAndGasProperties	4286000	USD
CY2020	us-gaap	Costs Incurred Exploration Costs CostsIncurredExplorationCosts	3891000	USD
CY2019	us-gaap	Costs Incurred Exploration Costs CostsIncurredExplorationCosts	2060000	USD
CY2018	us-gaap	Costs Incurred Exploration Costs CostsIncurredExplorationCosts	29365000	USD
CY2020	us-gaap	Costs Incurred Development Costs CostsIncurredDevelopmentCosts	355742000	USD
CY2019	us-gaap	Costs Incurred Development Costs CostsIncurredDevelopmentCosts	468498000	USD
CY2018	us-gaap	Costs Incurred Development Costs CostsIncurredDevelopmentCosts	332496000	USD
CY2020	us-gaap	Costs Incurred Asset Retirement Obligation Incurred CostsIncurredAssetRetirementObligationIncurred	62080000	USD
CY2019	us-gaap	Costs Incurred Asset Retirement Obligation Incurred CostsIncurredAssetRetirementObligationIncurred	26192000	USD
CY2018	nfg	Costs Incurred Reductionin Asset Retirement Obligation Costs Incurred CostsIncurredReductioninAssetRetirementObligationCostsIncurred	10107000	USD
CY2020	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties CostsIncurredAcquisitionOfOilAndGasProperties	710611000	USD
CY2019	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties CostsIncurredAcquisitionOfOilAndGasProperties	503565000	USD
CY2020	nfg	Results Of Operations Franchise Or Ad Valorem Taxes ResultsOfOperationsFranchiseOrAdValoremTaxes	15582000	USD
CY2018	us-gaap	Costs Incurred Acquisition Of Oil And Gas Properties CostsIncurredAcquisitionOfOilAndGasProperties	357584000	USD
CY2020	nfg	Costs Incurred Development Costs Capitalized Interest CostsIncurredDevelopmentCostsCapitalizedInterest	1000000.0	USD
CY2019	nfg	Costs Incurred Development Costs Capitalized Interest CostsIncurredDevelopmentCostsCapitalizedInterest	200000	USD
CY2018	nfg	Costs Incurred Development Costs Capitalized Interest CostsIncurredDevelopmentCostsCapitalizedInterest	300000	USD
CY2020	nfg	Amount Spent For Developing Proved Undeveloped Reserves AmountSpentForDevelopingProvedUndevelopedReserves	219900000	USD
CY2019	nfg	Amount Spent For Developing Proved Undeveloped Reserves AmountSpentForDevelopingProvedUndevelopedReserves	246000000.0	USD
CY2018	nfg	Amount Spent For Developing Proved Undeveloped Reserves AmountSpentForDevelopingProvedUndevelopedReserves	182300000	USD
CY2020	us-gaap	Results Of Operations Sales Or Transfers To Entitys Other Operations ResultsOfOperationsSalesOrTransfersToEntitysOtherOperations	1921000	USD
CY2019	us-gaap	Results Of Operations Sales Or Transfers To Entitys Other Operations ResultsOfOperationsSalesOrTransfersToEntitysOtherOperations	2532000	USD
CY2018	us-gaap	Results Of Operations Sales Or Transfers To Entitys Other Operations ResultsOfOperationsSalesOrTransfersToEntitysOtherOperations	2134000	USD
CY2020	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	510291000	USD
CY2019	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	630126000	USD
CY2018	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	558896000	USD
CY2020	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	203670000	USD
CY2019	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	186626000	USD
CY2018	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	162721000	USD
CY2019	nfg	Results Of Operations Franchise Or Ad Valorem Taxes ResultsOfOperationsFranchiseOrAdValoremTaxes	17673000	USD
CY2018	nfg	Results Of Operations Franchise Or Ad Valorem Taxes ResultsOfOperationsFranchiseOrAdValoremTaxes	14355000	USD
CY2020	nfg	Resultsof Operations Purchased Emission Allowance Expense ResultsofOperationsPurchasedEmissionAllowanceExpense	2930000	USD
CY2019	nfg	Resultsof Operations Purchased Emission Allowance Expense ResultsofOperationsPurchasedEmissionAllowanceExpense	2527000	USD
CY2018	nfg	Resultsof Operations Purchased Emission Allowance Expense ResultsofOperationsPurchasedEmissionAllowanceExpense	1883000	USD
CY2020	us-gaap	Results Of Operations Accretion Of Asset Retirement Obligations ResultsOfOperationsAccretionOfAssetRetirementObligations	5237000	USD
CY2019	us-gaap	Results Of Operations Accretion Of Asset Retirement Obligations ResultsOfOperationsAccretionOfAssetRetirementObligations	3723000	USD
CY2018	us-gaap	Results Of Operations Accretion Of Asset Retirement Obligations ResultsOfOperationsAccretionOfAssetRetirementObligations	4266000	USD
CY2020	nfg	Depreciation Depletion And Amortization Per Mcfe Of Production DepreciationDepletionAndAmortizationPerMcfeOfProduction	0.69	USD
CY2019	nfg	Depreciation Depletion And Amortization Per Mcfe Of Production DepreciationDepletionAndAmortizationPerMcfeOfProduction	0.71	USD
CY2018	nfg	Depreciation Depletion And Amortization Per Mcfe Of Production DepreciationDepletionAndAmortizationPerMcfeOfProduction	0.67	USD
CY2020	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	166759000	USD
CY2019	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	149881000	USD
CY2018	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	119946000	USD
CY2020	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	449438000	USD
CY2019	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	0	USD
CY2018	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	0	USD
CY2020	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	-92820000	USD
CY2019	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	64652000	USD
CY2018	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	72723000	USD
CY2020	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	-240505000	USD
CY2019	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	205044000	USD
CY2018	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	183002000	USD
CY2018	nfg	Results Of Operations Sales Revenue To Affiliated Enterprises ResultsOfOperationsSalesRevenueToAffiliatedEnterprises	0	USD
CY2020	nfg	Results Of Operations Sales Revenue To Affiliated Enterprises ResultsOfOperationsSalesRevenueToAffiliatedEnterprises	0	USD
CY2019	nfg	Results Of Operations Sales Revenue To Affiliated Enterprises ResultsOfOperationsSalesRevenueToAffiliatedEnterprises	0	USD
CY2019Q3	srt	Proved Undeveloped Reserve Volume ProvedUndevelopedReserveVolume	1018000000000	ft3
CY2020Q3	srt	Proved Undeveloped Reserve Volume ProvedUndevelopedReserveVolume	551000000000	ft3
CY2020	nfg	Proved Undeveloped Reserves As Percentage Of Total Proved Reserves ProvedUndevelopedReservesAsPercentageOfTotalProvedReserves	0.16
CY2019	nfg	Proved Undeveloped Reserves As Percentage Of Total Proved Reserves ProvedUndevelopedReservesAsPercentageOfTotalProvedReserves	0.33
CY2018Q3	srt	Proved Undeveloped Reserve Volume ProvedUndevelopedReserveVolume	757000000000	ft3
CY2019Q3	srt	Proved Undeveloped Reserve Volume ProvedUndevelopedReserveVolume	1018000000000	ft3
CY2019	nfg	Proved Undeveloped Reserves As Percentage Of Total Proved Reserves ProvedUndevelopedReservesAsPercentageOfTotalProvedReserves	0.33
CY2018	nfg	Proved Undeveloped Reserves As Percentage Of Total Proved Reserves ProvedUndevelopedReservesAsPercentageOfTotalProvedReserves	0.30
CY2020Q3	nfg	Proved Undeveloped Reserves Decrease ProvedUndevelopedReservesDecrease	467000000000	ft3
CY2020Q3	nfg	Proved Undeveloped Reserves Conversions To Developed Reserves ProvedUndevelopedReservesConversionsToDevelopedReserves	363000000000	ft3
CY2020Q3	nfg	Proved Undeveloped Reserves Removed ProvedUndevelopedReservesRemoved	179000000000	ft3
CY2020	nfg	Pud Well Locations Removed PUDWellLocationsRemoved	17
CY2020Q3	nfg	Proved Undeveloped Reserves Additions ProvedUndevelopedReservesAdditions	7000000000	ft3
CY2020Q3	nfg	Proved Undeveloped Reserves Upward Revisions ProvedUndevelopedReservesUpwardRevisions	20000000000	ft3
CY2020Q3	nfg	Proved Undeveloped Reserves Revisions ProvedUndevelopedReservesRevisions	48000000000	ft3
CY2020	nfg	Pud Well Locations Added PUDWellLocationsAdded	5
CY2016	nfg	Pud Well Locations Removed PUDWellLocationsRemoved	1
CY2017	nfg	Pud Well Locations Removed PUDWellLocationsRemoved	4
CY2019Q3	nfg	Proved Undeveloped Reserves Increase ProvedUndevelopedReservesIncrease	261000000000	ft3
CY2019Q3	nfg	Proved Undeveloped Reserves Additions ProvedUndevelopedReservesAdditions	575000000000	ft3
CY2019Q3	nfg	Proved Undeveloped Reserves Upward Revisions ProvedUndevelopedReservesUpwardRevisions	38000000000	ft3
CY2019Q3	nfg	Proved Undeveloped Reserves Conversions To Developed Reserves ProvedUndevelopedReservesConversionsToDevelopedReserves	297000000000	ft3
CY2019Q3	nfg	Proved Undeveloped Reserves Removed ProvedUndevelopedReservesRemoved	55000000000	ft3
CY2019	nfg	Pud Well Locations Removed PUDWellLocationsRemoved	6
CY2020	nfg	Capital Expenditures Related To Proved Undeveloped Reserves CapitalExpendituresRelatedToProvedUndevelopedReserves	220000000	USD
CY2020Q3	nfg	Proved Undeveloped Reserves Conversions To Developed Reserves ProvedUndevelopedReservesConversionsToDevelopedReserves	363000000000	ft3
CY2020	nfg	Conversion Of Undeveloped Proved Reserves To Developed Proved Reserves After Revisions Volume ConversionOfUndevelopedProvedReservesToDevelopedProvedReservesAfterRevisionsVolume	393000000000	ft3
CY2020Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.36
CY2020	nfg	Upward Revisionsto Pud Reserves Convertedto Developed Reserves UpwardRevisionstoPUDReservesConvertedtoDevelopedReserves	30000000000	ft3
CY2019	nfg	Capital Expenditures Related To Proved Undeveloped Reserves CapitalExpendituresRelatedToProvedUndevelopedReserves	246000000	USD
CY2019Q3	nfg	Proved Undeveloped Reserves Conversions To Developed Reserves ProvedUndevelopedReservesConversionsToDevelopedReserves	297000000000	ft3
CY2019	nfg	Conversion Of Undeveloped Proved Reserves To Developed Proved Reserves After Revisions Volume ConversionOfUndevelopedProvedReservesToDevelopedProvedReservesAfterRevisionsVolume	380000000000	ft3
CY2019Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.39
CY2019	nfg	Well Locations Developed With Net Pud Reserves WellLocationsDevelopedWithNetPUDReserves	56
CY2019	nfg	Percentof Well Locations Developed With Net Pud Reserves PercentofWellLocationsDevelopedWithNetPUDReserves	0.50
CY2019	nfg	Upward Revisionsto Pud Reserves Convertedto Developed Reserves UpwardRevisionstoPUDReservesConvertedtoDevelopedReserves	83000000000	ft3
CY2016Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.25
CY2017Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.27
CY2018Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.51
CY2019Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.39
CY2020Q3	nfg	Proved Undeveloped Reserves Percentage ProvedUndevelopedReservesPercentage	0.36
CY2020	nfg	Annual Discount For Estimated Timing Of Cash Flows AnnualDiscountForEstimatedTimingOfCashFlows	0.10
CY2019Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Net Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows	3791142000	USD
CY2020Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Cash Inflows FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows	6493362000	USD
CY2019Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Cash Inflows FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows	8738182000	USD
CY2018Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Cash Inflows FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows	7822855000	USD
CY2020Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Production Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts	3149857000	USD
CY2019Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Production Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts	2989518000	USD
CY2018Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Production Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts	2606411000	USD
CY2020Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Development Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesDevelopmentCosts	501678000	USD
CY2019Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Development Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesDevelopmentCosts	797640000	USD
CY2018Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Development Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesDevelopmentCosts	559707000	USD
CY2020Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Income Tax Expense FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense	454553000	USD
CY2019Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Income Tax Expense FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense	1159882000	USD
CY2018Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Income Tax Expense FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense	1125910000	USD
CY2020Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Net Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows	2387274000	USD
CY2018Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Net Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows	3530827000	USD
CY2020Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Ten Percent Annual Discount For Estimated Timing Of Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows	1164804000	USD
CY2019Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Ten Percent Annual Discount For Estimated Timing Of Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows	2054823000	USD
CY2018Q3	srt	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Ten Percent Annual Discount For Estimated Timing Of Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows	1810522000	USD
CY2020Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1222470000	USD
CY2019Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1736319000	USD
CY2018Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1720305000	USD
CY2019Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1736319000	USD
CY2018Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1720305000	USD
CY2017Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1113046000	USD
CY2020	srt	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	-290975000	USD
CY2019	srt	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	-425773000	USD
CY2018	srt	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	-381775000	USD
CY2020	srt	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	-1109101000	USD
CY2019	srt	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	-164428000	USD
CY2018	srt	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	541021000	USD
CY2020	srt	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	4236000	USD
CY2019	srt	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	202683000	USD
CY2018	srt	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	212494000	USD
CY2020	srt	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	99884000	USD
CY2019	srt	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-69254000	USD
CY2018	srt	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-43771000	USD
CY2020	srt	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	170363000	USD
CY2019	srt	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	0	USD
CY2018	srt	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	0	USD
CY2020	srt	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	0	USD
CY2019	srt	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	0	USD
CY2018	srt	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	100816000	USD
CY2020	srt	Previously Estimated Development Costs Incurred PreviouslyEstimatedDevelopmentCostsIncurred	219938000	USD
CY2019	srt	Previously Estimated Development Costs Incurred PreviouslyEstimatedDevelopmentCostsIncurred	245964000	USD
CY2018	srt	Previously Estimated Development Costs Incurred PreviouslyEstimatedDevelopmentCostsIncurred	182348000	USD
CY2020	srt	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	248182000	USD
CY2019	srt	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	21370000	USD
CY2018	srt	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	55558000	USD
CY2020	srt	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	-28337000	USD
CY2019	srt	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	53777000	USD
CY2018	srt	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	61363000	USD
CY2020	srt	Standardized Measure Of Discounted Future Net Cash Flow Relating To Proved Oil And Gas Reserves Accretion Of Discount StandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesAccretionOfDiscount	171961000	USD
CY2019	srt	Standardized Measure Of Discounted Future Net Cash Flow Relating To Proved Oil And Gas Reserves Accretion Of Discount StandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesAccretionOfDiscount	151675000	USD
CY2018	srt	Standardized Measure Of Discounted Future Net Cash Flow Relating To Proved Oil And Gas Reserves Accretion Of Discount StandardizedMeasureOfDiscountedFutureNetCashFlowRelatingToProvedOilAndGasReservesAccretionOfDiscount	80837000	USD
CY2020Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1222470000	USD
CY2019Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1736319000	USD
CY2018Q3	srt	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	1720305000	USD
CY2019	nfg	Reversalof Estimate For Potential Sequestrationof Amt Credit Refunds Under2017 Tax Reform Ac ReversalofEstimateForPotentialSequestrationofAMTCreditRefundsUnder2017TaxReformAc	5000000.0	USD

Files In Submission

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$NFG
NATIONAL FUEL GAS CO Stock $nfg

2020 Q3 Form 10-K Financial Statement

#000007014520000032 Filed on November 20, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$NFG NATIONAL FUEL GAS CO Stock $nfg

2020 Q3 Form 10-K Financial Statement

#000007014520000032 Filed on November 20, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$NFG
NATIONAL FUEL GAS CO Stock $nfg