$NMIH
NMI Holdings, Inc. Stock $nmih

$nmih Overview Financials Valuation SEC Filings Company Website

2021 Q2 Form 10-Q Financial Statement

#000154790321000145 Filed on August 04, 2021

Income Statement

Concept	2021 Q2	2020 Q2
Revenue	$120.8M	$107.9M
YoY Change	11.87%	18.39%
Cost Of Revenue	$4.640M
YoY Change
Gross Profit	$116.1M
YoY Change
Gross Profit Margin	96.16%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$2.644M	$2.500M
YoY Change	5.76%	13.64%
% of Gross Profit	2.28%
Operating Expenses	$39.85M	$65.80M
YoY Change	-39.44%	85.35%
Operating Profit	$76.28M
YoY Change
Interest Expense	$7.922M	$5.941M
YoY Change	33.34%	93.45%
% of Operating Profit	10.39%
Other Income/Expense, Net
YoY Change
Pretax Income	$73.66M	$34.98M
YoY Change	110.58%	-31.36%
Income Tax	$16.13M	$8.129M
% Of Pretax Income	21.9%	23.24%
Net Earnings	$57.52M	$26.85M
YoY Change	114.25%	-31.34%
Net Earnings / Revenue	47.63%	24.87%
Basic Earnings Per Share	$0.67	$0.36
Diluted Earnings Per Share	$0.65	$0.36
COMMON SHARES
Basic Shares Outstanding	85.65M shares	73.62M shares
Diluted Shares Outstanding	86.82M shares	74.17M shares

Balance Sheet

Concept	2021 Q2	2020 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$68.08M	$515.5M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$31.44M	$26.11M
YoY Change	20.45%	1.08%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$1.994B	$1.340B
YoY Change	48.85%	31.66%
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$2.306B	$2.047B
YoY Change	12.65%	67.73%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$56.80M	$104.8M
YoY Change	-45.8%	329.51%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$56.80M	$104.8M
YoY Change	-45.8%	329.51%
LONG-TERM LIABILITIES
Long-Term Debt	$393.9M	$392.8M
YoY Change	0.29%	168.49%
Other Long-Term Liabilities	$8.661M	$11.20M
YoY Change	-22.67%	-47.42%
Total Long-Term Liabilities	$402.6M	$404.0M
YoY Change	-0.34%	141.05%
TOTAL LIABILITIES
Total Short-Term Liabilities	$56.80M	$104.8M
Total Long-Term Liabilities	$402.6M	$404.0M
Total Liabilities	$846.0M	$789.9M
YoY Change	7.1%	93.59%
SHAREHOLDERS EQUITY
Retained Earnings	$487.4M	$290.6M
YoY Change	67.75%	175.45%
Common Stock
YoY Change
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.460B	$1.257B
YoY Change
Total Liabilities & Shareholders Equity	$2.306B	$2.047B
YoY Change	12.65%	67.73%

Cashflow Statement

Concept	2021 Q2	2020 Q2
OPERATING ACTIVITIES
Net Income	$57.52M	$26.85M
YoY Change	114.25%	-31.34%
Depreciation, Depletion And Amortization	$2.644M	$2.500M
YoY Change	5.76%	13.64%
Cash From Operating Activities	$97.04M	$79.50M
YoY Change	22.07%	34.75%
INVESTING ACTIVITIES
Capital Expenditures	-$3.550M	-$3.100M
YoY Change	14.52%	14.81%
Acquisitions
YoY Change
Other Investing Activities	-$140.6M	-$137.0M
YoY Change	2.65%	127.2%
Cash From Investing Activities	-$144.3M	-$140.1M
YoY Change	2.98%	122.38%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-322.0K	466.2M
YoY Change	-100.07%	-466300.0%
NET CHANGE
Cash From Operating Activities	97.04M	79.50M
Cash From Investing Activities	-144.3M	-140.1M
Cash From Financing Activities	-322.0K	466.2M
Net Change In Cash	-47.56M	405.6M
YoY Change	-111.73%	-9992.68%
FREE CASH FLOW
Cash From Operating Activities	$97.04M	$79.50M
Capital Expenditures	-$3.550M	-$3.100M
Free Cash Flow	$100.6M	$82.60M
YoY Change	21.78%	33.87%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Entity Central Index Key EntityCentralIndexKey	0001547903
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Amendment Flag AmendmentFlag	false
CY2021Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1954187000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1730835000	USD
CY2021Q2	us-gaap	Restricted Cash RestrictedCash	4159000	USD
CY2020Q4	us-gaap	Restricted Cash RestrictedCash	5555000	USD
CY2021Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2021Q2	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	85703487	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	85163039	shares
CY2021Q2	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	85703487	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	85163039	shares
CY2021Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	250000000	shares
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	250000000	shares
CY2021Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	4995000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	8978000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-7003000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	5162000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	3000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	149000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	3000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-258000	USD
CY2021Q1	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	-11997000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	4992000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	-3409000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	-8829000	USD
	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2021-06-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	001-36174
	dei	Entity Registrant Name EntityRegistrantName	NMI Holdings, Inc.
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	45-4914248
	dei	Entity Address Address Line1 EntityAddressAddressLine1	2100 Powell Street
	dei	Entity Address City Or Town EntityAddressCityOrTown	Emeryville
	dei	Entity Address State Or Province EntityAddressStateOrProvince	CA
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	94608
	dei	City Area Code CityAreaCode	855
	dei	Local Phone Number LocalPhoneNumber	530-6642
	dei	Security12b Title Security12bTitle	Class A Common Stock, par value $0.01
	dei	Trading Symbol TradingSymbol	NMIH
	dei	Security Exchange Name SecurityExchangeName	NASDAQ
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
CY2021Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	85708239	shares
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1994280000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1804286000	USD
CY2021Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	68080000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	126937000	USD
CY2021Q2	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	55939000	USD
CY2020Q4	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	49779000	USD
CY2021Q2	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	11148000	USD
CY2020Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	9862000	USD
CY2021Q2	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	4095000	USD
CY2020Q4	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	3292000	USD
CY2021Q2	us-gaap	Deferred Policy Acquisition Costs DeferredPolicyAcquisitionCosts	62137000	USD
CY2020Q4	us-gaap	Deferred Policy Acquisition Costs DeferredPolicyAcquisitionCosts	62225000	USD
CY2021Q2	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	31443000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	29665000	USD
CY2021Q2	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	3634000	USD
CY2020Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	3634000	USD
CY2021Q2	us-gaap	Prepaid Reinsurance Premiums PrepaidReinsurancePremiums	3831000	USD
CY2020Q4	us-gaap	Prepaid Reinsurance Premiums PrepaidReinsurancePremiums	6190000	USD
CY2021Q2	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	19726000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	17608000	USD
CY2021Q2	us-gaap	Other Assets OtherAssets	51565000	USD
CY2020Q4	us-gaap	Other Assets OtherAssets	53188000	USD
CY2021Q2	us-gaap	Assets Assets	2305878000	USD
CY2020Q4	us-gaap	Assets Assets	2166666000	USD
CY2021Q2	us-gaap	Secured Debt SecuredDebt	393949000	USD
CY2020Q4	us-gaap	Secured Debt SecuredDebt	393301000	USD
CY2021Q2	us-gaap	Unearned Premiums UnearnedPremiums	142148000	USD
CY2020Q4	us-gaap	Unearned Premiums UnearnedPremiums	118817000	USD
CY2021Q2	us-gaap	Accounts Payable And Accrued Liabilities Current And Noncurrent AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent	56803000	USD
CY2020Q4	us-gaap	Accounts Payable And Accrued Liabilities Current And Noncurrent AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent	61716000	USD
CY2021Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	101235000	USD
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	90567000	USD
CY2021Q2	us-gaap	Funds Held Under Reinsurance Agreements Liability FundsHeldUnderReinsuranceAgreementsLiability	6904000	USD
CY2020Q4	us-gaap	Funds Held Under Reinsurance Agreements Liability FundsHeldUnderReinsuranceAgreementsLiability	8653000	USD
CY2021Q2	us-gaap	Warrants And Rights Outstanding WarrantsAndRightsOutstanding	3385000	USD
CY2020Q4	us-gaap	Warrants And Rights Outstanding WarrantsAndRightsOutstanding	4409000	USD
CY2021Q2	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	136273000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	112586000	USD
CY2021Q2	us-gaap	Other Liabilities OtherLiabilities	5276000	USD
CY2020Q4	us-gaap	Other Liabilities OtherLiabilities	7026000	USD
CY2021Q2	us-gaap	Liabilities Liabilities	845973000	USD
CY2020Q4	us-gaap	Liabilities Liabilities	797075000	USD
CY2021Q2	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2021Q2	us-gaap	Common Stock Value Outstanding CommonStockValueOutstanding	857000	USD
CY2020Q4	us-gaap	Common Stock Value Outstanding CommonStockValueOutstanding	852000	USD
CY2021Q2	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	944121000	USD
CY2020Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	937872000	USD
CY2021Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	27503000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	53856000	USD
CY2021Q2	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	487424000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	377011000	USD
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	1459905000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	1369591000	USD
CY2021Q2	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2305878000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2166666000	USD
CY2020Q2	us-gaap	Premiums Earned Net PremiumsEarnedNet	98944000	USD
CY2021Q2	us-gaap	Premiums Earned Net PremiumsEarnedNet	110888000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	216767000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	197661000	USD
CY2021Q2	us-gaap	Net Investment Income NetInvestmentIncome	9382000	USD
CY2020Q2	us-gaap	Net Investment Income NetInvestmentIncome	7070000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	18196000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	15174000	USD
CY2021Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	12000	USD
CY2020Q2	us-gaap	Gain Loss On Investments GainLossOnInvestments	711000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	12000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	639000	USD
CY2021Q2	us-gaap	Other Income OtherIncome	483000	USD
CY2020Q2	us-gaap	Other Income OtherIncome	1223000	USD
	us-gaap	Other Income OtherIncome	984000	USD
	us-gaap	Other Income OtherIncome	2123000	USD
CY2021Q2	us-gaap	Revenues Revenues	120765000	USD
CY2020Q2	us-gaap	Revenues Revenues	107948000	USD
	us-gaap	Revenues Revenues	235959000	USD
	us-gaap	Revenues Revenues	215597000	USD
CY2021Q2	us-gaap	Incurred Claims Property Casualty And Liability IncurredClaimsPropertyCasualtyAndLiability	4640000	USD
CY2020Q2	us-gaap	Incurred Claims Property Casualty And Liability IncurredClaimsPropertyCasualtyAndLiability	34334000	USD
	us-gaap	Incurred Claims Property Casualty And Liability IncurredClaimsPropertyCasualtyAndLiability	9602000	USD
	us-gaap	Incurred Claims Property Casualty And Liability IncurredClaimsPropertyCasualtyAndLiability	40031000	USD
CY2021Q2	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	34725000	USD
CY2020Q2	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	30370000	USD
	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	68790000	USD
	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	62647000	USD
CY2021Q2	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	481000	USD
CY2020Q2	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	1090000	USD
	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	1072000	USD
	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	1824000	USD
CY2021Q2	us-gaap	Interest Expense InterestExpense	7922000	USD
CY2020Q2	us-gaap	Interest Expense InterestExpense	5941000	USD
	us-gaap	Interest Expense InterestExpense	15837000	USD
	us-gaap	Interest Expense InterestExpense	8685000	USD
CY2021Q2	nmih	Gain Losson Changein Fair Valueof Warrant Liability GainLossonChangeinFairValueofWarrantLiability	658000	USD
CY2020Q2	nmih	Gain Losson Changein Fair Valueof Warrant Liability GainLossonChangeinFairValueofWarrantLiability	-1236000	USD
	nmih	Gain Losson Changein Fair Valueof Warrant Liability GainLossonChangeinFairValueofWarrantLiability	453000	USD
	nmih	Gain Losson Changein Fair Valueof Warrant Liability GainLossonChangeinFairValueofWarrantLiability	4723000	USD
CY2021Q2	us-gaap	Costs And Expenses CostsAndExpenses	47110000	USD
CY2020Q2	us-gaap	Costs And Expenses CostsAndExpenses	72971000	USD
	us-gaap	Costs And Expenses CostsAndExpenses	94848000	USD
	us-gaap	Costs And Expenses CostsAndExpenses	108464000	USD
CY2021Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	73655000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	34977000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	141111000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	107133000	USD
CY2021Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	16133000	USD
CY2020Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	8129000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30697000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	22014000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	57522000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	26848000	USD
	us-gaap	Net Income Loss NetIncomeLoss	110414000	USD
	us-gaap	Net Income Loss NetIncomeLoss	85119000	USD
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.67
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.36
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.29
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.20
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.65
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.36
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.27
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.11
CY2021Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85647000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73617000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85483000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71090000	shares
CY2021Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	86819000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	74174000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	86729000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	72407000	shares
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	57522000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	26848000	USD
	us-gaap	Net Income Loss NetIncomeLoss	110414000	USD
	us-gaap	Net Income Loss NetIncomeLoss	85119000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	18790000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	33773000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-26343000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	19418000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	10000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	562000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	10000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-969000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	18780000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	33211000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-26353000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	20387000	USD
CY2021Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	76302000	USD
CY2020Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	60059000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	84061000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	105506000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	1369591000	USD
CY2021Q1	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	557000	USD
CY2021Q1	nmih	Stock Issued During Period Value Employee Stock Purchase Plan Netof Tax Withholdings StockIssuedDuringPeriodValueEmployeeStockPurchasePlanNetofTaxWithholdings	-620000	USD
CY2021Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3022000	USD
CY2021Q1	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-45133000	USD
CY2021Q1	us-gaap	Net Income Loss NetIncomeLoss	52891000	USD
CY2021Q1	us-gaap	Stockholders Equity StockholdersEquity	1380308000	USD
CY2021Q2	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	197000	USD
CY2021Q2	nmih	Stock Issued During Period Value Employee Stock Purchase Plan Netof Tax Withholdings StockIssuedDuringPeriodValueEmployeeStockPurchasePlanNetofTaxWithholdings	-285000	USD
CY2021Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3383000	USD
CY2021Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	18780000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	57522000	USD
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	1459905000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	930420000	USD
CY2020Q1	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	221000	USD
CY2020Q1	nmih	Stock Issued During Period Value Employee Stock Purchase Plan Netof Tax Withholdings StockIssuedDuringPeriodValueEmployeeStockPurchasePlanNetofTaxWithholdings	-3750000	USD
CY2020Q1	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2552000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-12824000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	58271000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	974890000	USD
CY2020Q2	us-gaap	Stock Issued During Period Value Conversion Of Convertible Securities StockIssuedDuringPeriodValueConversionOfConvertibleSecurities	219687000	USD
CY2020Q2	nmih	Stock Issued During Period Value Employee Stock Purchase Plan Netof Tax Withholdings StockIssuedDuringPeriodValueEmployeeStockPurchasePlanNetofTaxWithholdings	-321000	USD
CY2020Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2722000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	33211000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	26848000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	1257037000	USD
	us-gaap	Net Income Loss NetIncomeLoss	110414000	USD
	us-gaap	Net Income Loss NetIncomeLoss	85119000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	12000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	639000	USD
	us-gaap	Fair Value Adjustment Of Warrants FairValueAdjustmentOfWarrants	-453000	USD
	us-gaap	Fair Value Adjustment Of Warrants FairValueAdjustmentOfWarrants	-4723000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	5344000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	4914000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-3289000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-629000	USD
	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	893000	USD
	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	3267000	USD
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	30692000	USD
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	22006000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	6405000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	5274000	USD
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	6160000	USD
	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	323000	USD
	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	1286000	USD
	us-gaap	Increase Decrease In Accrued Investment Income Receivable IncreaseDecreaseInAccruedInvestmentIncomeReceivable	1078000	USD
	us-gaap	Increase Decrease In Prepaid Expense IncreaseDecreaseInPrepaidExpense	803000	USD
	us-gaap	Increase Decrease In Prepaid Expense IncreaseDecreaseInPrepaidExpense	-96000	USD
	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	-88000	USD
	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	3647000	USD
	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-230000	USD
	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	328000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	23331000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	-21406000	USD
	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	10668000	USD
	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	46151000	USD
	us-gaap	Increase Decrease In Reinsurance Recoverable IncreaseDecreaseInReinsuranceRecoverable	2118000	USD
	us-gaap	Increase Decrease In Reinsurance Recoverable IncreaseDecreaseInReinsuranceRecoverable	9368000	USD
	nmih	Increase Decreasein Reinsurance Assetsand Liabilities IncreaseDecreaseinReinsuranceAssetsandLiabilities	-9000	USD
	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	41872000	USD
	nmih	Increase Decreasein Reinsurance Assetsand Liabilities IncreaseDecreaseinReinsuranceAssetsandLiabilities	-2658000	USD
	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	2013000	USD
	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-1247000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	182544000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	127355000	USD
	us-gaap	Payments To Acquire Short Term Investments PaymentsToAcquireShortTermInvestments	8991000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	286635000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	451462000	USD
	us-gaap	Proceeds From Sale Of Short Term Investments ProceedsFromSaleOfShortTermInvestments	0	USD
	us-gaap	Proceeds From Sale Of Short Term Investments ProceedsFromSaleOfShortTermInvestments	85689000	USD
	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	60997000	USD
	us-gaap	Proceeds From Sale And Maturity Of Available For Sale Securities ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities	297977000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	6050000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	4638000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-240679000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-114306000	USD
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	220284000	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	4043000	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans Including Stock Options ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	3391000	USD
	us-gaap	Proceeds From Warrant Exercises ProceedsFromWarrantExercises	183000	USD
	us-gaap	Proceeds From Warrant Exercises ProceedsFromWarrantExercises	0	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	4948000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	7462000	USD
	us-gaap	Proceeds From Issuance Of Senior Long Term Debt ProceedsFromIssuanceOfSeniorLongTermDebt	0	USD
	us-gaap	Proceeds From Issuance Of Senior Long Term Debt ProceedsFromIssuanceOfSeniorLongTermDebt	400000000	USD
	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	0	USD
	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	147750000	USD
	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	USD
	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	7151000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-722000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	461312000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-58857000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	474361000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	126937000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	41089000	USD
CY2021Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	68080000	USD
CY2020Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	515450000	USD
	us-gaap	Interest Paid Net InterestPaidNet	14750000	USD
	us-gaap	Interest Paid Net InterestPaidNet	4286000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	457000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	76000	USD
CY2021Q2	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	50	state
CY2021Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1954187000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	49061000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	8968000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1994280000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1730835000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	73963000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	512000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1804286000	USD
CY2021Q2	nmih	Debt Securities Corporate Component Of Total.Percentage DebtSecuritiesCorporateComponentOfTotal.Percentage	1
CY2020Q4	nmih	Debt Securities Corporate Component Of Total.Percentage DebtSecuritiesCorporateComponentOfTotal.Percentage	1
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	71762000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	72265000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	581153000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	605423000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	1127385000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	1140283000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	60381000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	60949000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	113506000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	115360000	USD
CY2021Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1954187000	USD
CY2021Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1994280000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	57429000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	57949000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	507444000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	536520000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	1016230000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	1056098000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	21261000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	22539000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	128471000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	131180000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	1730835000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	1804286000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	9000000.0	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	512000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	8000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	173	security
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	644999000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	8968000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	0	security
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	0	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	0	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	173	security
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	644999000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	8968000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	15	security
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	48820000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	504000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	2	security
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	2528000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	8000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	17	security
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	51348000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	512000	USD
CY2021Q2	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	9608000	USD
CY2020Q2	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	7320000	USD
	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	18833000	USD
	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	15669000	USD
CY2021Q2	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	226000	USD
CY2020Q2	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	250000	USD
	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	637000	USD
	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	495000	USD
CY2021Q2	us-gaap	Investment Income Net InvestmentIncomeNet	9382000	USD
CY2020Q2	us-gaap	Investment Income Net InvestmentIncomeNet	7070000	USD
	us-gaap	Investment Income Net InvestmentIncomeNet	18196000	USD
	us-gaap	Investment Income Net InvestmentIncomeNet	15174000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	12000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	4586000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	12000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	5126000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	3875000	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	USD
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	4487000	USD
CY2021Q2	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	12000	USD
CY2020Q2	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	711000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	12000	USD
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	639000	USD
CY2021Q2	us-gaap	Direct Premiums Written DirectPremiumsWritten	148944000	USD
CY2020Q2	us-gaap	Direct Premiums Written DirectPremiumsWritten	108478000	USD
	us-gaap	Direct Premiums Written DirectPremiumsWritten	285176000	USD
	us-gaap	Direct Premiums Written DirectPremiumsWritten	211931000	USD
CY2021Q2	us-gaap	Ceded Premiums Written CededPremiumsWritten	22302000	USD
CY2020Q2	us-gaap	Ceded Premiums Written CededPremiumsWritten	18369000	USD
	us-gaap	Ceded Premiums Written CededPremiumsWritten	42719000	USD
	us-gaap	Ceded Premiums Written CededPremiumsWritten	30451000	USD
CY2021Q2	us-gaap	Premiums Written Net PremiumsWrittenNet	126642000	USD
CY2020Q2	us-gaap	Premiums Written Net PremiumsWrittenNet	90109000	USD
	us-gaap	Premiums Written Net PremiumsWrittenNet	242457000	USD
	us-gaap	Premiums Written Net PremiumsWrittenNet	181480000	USD
CY2021Q2	us-gaap	Direct Premiums Earned DirectPremiumsEarned	134203000	USD
CY2020Q2	us-gaap	Direct Premiums Earned DirectPremiumsEarned	120150000	USD
	us-gaap	Direct Premiums Earned DirectPremiumsEarned	261846000	USD
	us-gaap	Direct Premiums Earned DirectPremiumsEarned	233337000	USD
CY2021Q2	us-gaap	Ceded Premiums Earned CededPremiumsEarned	23315000	USD
CY2020Q2	us-gaap	Ceded Premiums Earned CededPremiumsEarned	21206000	USD
	us-gaap	Ceded Premiums Earned CededPremiumsEarned	45079000	USD
	us-gaap	Ceded Premiums Earned CededPremiumsEarned	35676000	USD
CY2021Q2	us-gaap	Premiums Earned Net PremiumsEarnedNet	110888000	USD
CY2020Q2	us-gaap	Premiums Earned Net PremiumsEarnedNet	98944000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	216767000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	197661000	USD
CY2021Q2	us-gaap	Restricted Cash RestrictedCash	4200000	USD
CY2020Q4	us-gaap	Restricted Cash RestrictedCash	5600000	USD
CY2021Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Number Of Primary Loans In Default LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsNumberOfPrimaryLoansInDefault	8764	loan
CY2021Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	101200000	USD
	nmih	Liabilityfor Paid Claimsand Claims Adjustment Expense Numberof Paid Claims LiabilityforPaidClaimsandClaimsAdjustmentExpenseNumberofPaidClaims	35	claim
	nmih	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Claims Paid Including Amounts Covered By Insurance LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseClaimsPaidIncludingAmountsCoveredByInsurance	1300000	USD
CY2021Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Number Of Primary Loans In Default LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsNumberOfPrimaryLoansInDefault	8764	loan
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	12000	USD
CY2021Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Number Of Primary Loans In Default Percent Of Total Policies In Force LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsNumberOfPrimaryLoansInDefaultPercentOfTotalPoliciesInForce	0.0186
CY2021Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Total Policies In Force LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsTotalPoliciesInForce	471794	claim
CY2020Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Number Of Primary Loans In Default LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsNumberOfPrimaryLoansInDefault	10816	loan
CY2020Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Number Of Primary Loans In Default Percent Of Total Policies In Force LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsNumberOfPrimaryLoansInDefaultPercentOfTotalPoliciesInForce	0.0290
CY2020Q2	nmih	Liability For Unpaid Claims And Claims Adjustment Expense Incurred But Not Reported Ibnr Claims Total Policies In Force LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredButNotReportedIBNRClaimsTotalPoliciesInForce	372934	policy
	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="margin-bottom:9pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The following table provides a reconciliation of the beginning and ending gross reserve balances for primary insurance claims and claim expenses:</span></div><div style="margin-bottom:9pt;text-align:justify"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:100.000%"><tr><td style="width:1.0%"/><td style="width:67.434%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:14.273%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.518%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:14.275%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="9" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">For the six months ended June 30,</span></td></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2021</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="border-bottom:1pt solid #000000;border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2020</span></td></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="9" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-style:italic;font-weight:400;line-height:100%">(In Thousands)</span></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Beginning balance</span></td><td style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">90,567 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">23,752 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Less reinsurance recoverables </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:6.5pt;font-weight:400;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline">(1)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(17,608)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(4,939)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Beginning balance, net of reinsurance recoverables</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">72,959 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">18,813 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:6pt"><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Add claims incurred:</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 12.25pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Claims and claim expenses incurred:</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:24.75pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Current year </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:6.5pt;font-weight:400;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline">(2)</span></div></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">15,626 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">42,516 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:24.75pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Prior years</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:6.5pt;font-weight:400;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline"> (3)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(6,024)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(2,485)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Total claims and claim expenses incurred</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">9,602 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">40,031 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:8pt"><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Less claims paid:</span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 12.25pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Claims and claim expenses paid:</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Current year </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:6.5pt;font-weight:400;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline">(2)</span></div></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">12 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">39 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:24.75pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Prior years </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:6.5pt;font-weight:400;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline">(3)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">1,040 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3,209 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Total claims and claim expenses paid</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">1,052 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">3,248 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:6pt"><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Reserve at end of period, net of reinsurance recoverables</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">81,509 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">55,596 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Add reinsurance recoverables </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:6.5pt;font-weight:400;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline">(1)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">19,726 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">14,307 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Ending balance</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000;border-top:1pt solid #000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000;border-top:1pt solid #000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">101,235 </span></td><td style="background-color:#cceeff;border-bottom:3pt double #000;border-top:1pt solid #000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:100%">69,903 </span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr></table></div><div style="padding-left:18pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:400;line-height:120%;position:relative;top:-2.8pt;vertical-align:baseline">(1) </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">Related to ceded losses recoverable under the QSR Transactions. See Note 5, "</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-style:italic;font-weight:400;line-height:120%">Reinsurance</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">" for additional information.</span></div><div style="padding-left:18pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:400;line-height:120%;position:relative;top:-2.8pt;vertical-align:baseline">(2) </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">Related to insured loans with their most recent defaults occurring in the current year. For example, if a loan defaulted in a prior year and subsequently cured and later re-defaulted in the current year, the default would be included in the current year. Amounts are presented net of reinsurance and included $9.8 million attributed to net case reserves and $5.6 million attributed to net IBNR reserves for the six months ended June 30, 2021 and $34.7 million attributed to net case reserves and $7.1 million attributed to net IBNR reserves for the six months ended June 30, 2020.</span></div><div style="padding-left:18pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:400;line-height:120%;position:relative;top:-2.8pt;vertical-align:baseline">(3) </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">Related to insured loans with defaults occurring in prior years, which have been continuously in default before the start of the current year. Amounts are presented net of reinsurance and included $1.1 million attributed to net case reserves and $5.0 million attributed to net IBNR reserves for the six months ended June 30, 2021 and $1.1 million attributed to net case reserves and $1.3 million attributed to net IBNR reserves for the six months ended June 30, 2020.</span></div>
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	90567000	USD
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	23752000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables On Paid And Unpaid Losses ReinsuranceRecoverablesOnPaidAndUnpaidLosses	17608000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables On Paid And Unpaid Losses ReinsuranceRecoverablesOnPaidAndUnpaidLosses	4939000	USD
CY2020Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	72959000	USD
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	18813000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	15626000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	42516000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-6024000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-2485000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	9602000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	40031000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	39000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	1040000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	3209000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	1052000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3248000	USD
CY2021Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	81509000	USD
CY2020Q2	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	55596000	USD
CY2021Q2	us-gaap	Reinsurance Recoverables On Paid And Unpaid Losses ReinsuranceRecoverablesOnPaidAndUnpaidLosses	19726000	USD
CY2020Q2	us-gaap	Reinsurance Recoverables On Paid And Unpaid Losses ReinsuranceRecoverablesOnPaidAndUnpaidLosses	14307000	USD
CY2021Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	101235000	USD
CY2020Q2	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	69903000	USD
	nmih	Current Year Claims And Claims Adjustment Expense Case Reserves CurrentYearClaimsAndClaimsAdjustmentExpenseCaseReserves	9800000	USD
	nmih	Current Year Claims And Claims Adjustment Expense Incurred But Not Reported CurrentYearClaimsAndClaimsAdjustmentExpenseIncurredButNotReported	5600000	USD
	nmih	Current Year Claims And Claims Adjustment Expense Case Reserves CurrentYearClaimsAndClaimsAdjustmentExpenseCaseReserves	34700000	USD
	nmih	Current Year Claims And Claims Adjustment Expense Incurred But Not Reported CurrentYearClaimsAndClaimsAdjustmentExpenseIncurredButNotReported	7100000	USD
	nmih	Prior Year Claims And Claims Adjustment Expense Case Reserves PriorYearClaimsAndClaimsAdjustmentExpenseCaseReserves	1100000	USD
	nmih	Prior Year Claims And Claims Adjustment Expense Incurred But Not Reported PriorYearClaimsAndClaimsAdjustmentExpenseIncurredButNotReported	5000000.0	USD
	nmih	Prior Year Claims And Claims Adjustment Expense Case Reserves PriorYearClaimsAndClaimsAdjustmentExpenseCaseReserves	1100000	USD
	nmih	Prior Year Claims And Claims Adjustment Expense Incurred But Not Reported PriorYearClaimsAndClaimsAdjustmentExpenseIncurredButNotReported	1300000	USD
CY2021Q2	nmih	Liabilityfor Prior Year Claimsand Claims Adjustment Expense LiabilityforPriorYearClaimsandClaimsAdjustmentExpense	81800000	USD
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	57522000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	26848000	USD
	us-gaap	Net Income Loss NetIncomeLoss	110414000	USD
	us-gaap	Net Income Loss NetIncomeLoss	85119000	USD
CY2021Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85647000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73617000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85483000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71090000	shares
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.67
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.36
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.29
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.20
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	57522000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	26848000	USD
	us-gaap	Net Income Loss NetIncomeLoss	110414000	USD
	us-gaap	Net Income Loss NetIncomeLoss	85119000	USD
CY2021Q2	nmih	Gain From Change In Fair Value Of Warrant Liability GainFromChangeInFairValueOfWarrantLiability	-658000	USD
CY2020Q2	nmih	Gain From Change In Fair Value Of Warrant Liability GainFromChangeInFairValueOfWarrantLiability	0	USD
	nmih	Gain From Change In Fair Value Of Warrant Liability GainFromChangeInFairValueOfWarrantLiability	-453000	USD
	nmih	Gain From Change In Fair Value Of Warrant Liability GainFromChangeInFairValueOfWarrantLiability	-4723000	USD
CY2021Q2	us-gaap	Net Income Loss Attributable To Parent Diluted NetIncomeLossAttributableToParentDiluted	56864000	USD
CY2020Q2	us-gaap	Net Income Loss Attributable To Parent Diluted NetIncomeLossAttributableToParentDiluted	26848000	USD
	us-gaap	Net Income Loss Attributable To Parent Diluted NetIncomeLossAttributableToParentDiluted	109961000	USD
	us-gaap	Net Income Loss Attributable To Parent Diluted NetIncomeLossAttributableToParentDiluted	80396000	USD
CY2021Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85647000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	73617000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	85483000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	71090000	shares
CY2021Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1172000	shares
CY2020Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	557000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1246000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1317000	shares
CY2021Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	86819000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	74174000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	86729000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	72407000	shares
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.65
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.36
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.27
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.11
CY2021Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	2000	shares
CY2020Q2	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	609000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1000	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	78000	shares
CY2012Q2	us-gaap	Warrants And Rights Outstanding WarrantsAndRightsOutstanding	5100000	USD
CY2012Q2	us-gaap	Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights	992000	shares
CY2021Q2	us-gaap	Class Of Warrant Or Right Outstanding ClassOfWarrantOrRightOutstanding	271000	shares
CY2012Q2	nmih	Number Of Shares Right To Purchase Per Warrant NumberOfSharesRightToPurchasePerWarrant	1	shares
CY2012Q2	us-gaap	Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1	10.00
CY2021Q2	nmih	Classof Warrantor Right Numberof Warrants Exercised During Period ClassofWarrantorRightNumberofWarrantsExercisedDuringPeriod	14000	shares
CY2021Q2	us-gaap	Stock Issued During Period Shares Conversion Of Convertible Securities StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	8000	shares
CY2021Q2	nmih	Class Of Warrant Or Right Fair Value Of Warrant Liability Reclassified To Additional Paid In Capital Upon Exercise ClassOfWarrantOrRightFairValueOfWarrantLiabilityReclassifiedToAdditionalPaidInCapitalUponExercise	200000	USD
	nmih	Classof Warrantor Right Numberof Warrants Exercised During Period ClassofWarrantorRightNumberofWarrantsExercisedDuringPeriod	41000	shares
	us-gaap	Stock Issued During Period Shares Conversion Of Convertible Securities StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	32000	shares
	nmih	Class Of Warrant Or Right Fair Value Of Warrant Liability Reclassified To Additional Paid In Capital Upon Exercise ClassOfWarrantOrRightFairValueOfWarrantLiabilityReclassifiedToAdditionalPaidInCapitalUponExercise	600000	USD
CY2020Q2	nmih	Classof Warrantor Right Numberof Warrants Exercised During Period ClassofWarrantorRightNumberofWarrantsExercisedDuringPeriod	0	shares
	nmih	Classof Warrantor Right Numberof Warrants Exercised During Period ClassofWarrantorRightNumberofWarrantsExercisedDuringPeriod	9000	shares
	us-gaap	Stock Issued During Period Shares Conversion Of Convertible Securities StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities	6000	shares
	nmih	Class Of Warrant Or Right Fair Value Of Warrant Liability Reclassified To Additional Paid In Capital Upon Exercise ClassOfWarrantOrRightFairValueOfWarrantLiabilityReclassifiedToAdditionalPaidInCapitalUponExercise	200000	USD
CY2021Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.219
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.218
CY2020Q2	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.232
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.205
CY2021Q2	nmih	Tax And Loss Bond TaxAndLossBond	46400000	USD
CY2020Q4	nmih	Tax And Loss Bond TaxAndLossBond	46400000	USD
	us-gaap	Premiums Receivable Note PremiumsReceivableNote	Premium Receivable <div style="text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Premiums receivable consists of premiums due on our mortgage insurance policies. If a mortgage insurance premium is unpaid for more than 120 days, all associated receivables are written off against earned premium and the related insurance policy is canceled. We recognize an allowance for credit losses for premiums receivable based on credit losses expected to arise over the life of the receivable. Due to the nature of our insurance policies (a necessary precondition for access to mortgage credit for covered borrowers) and the short duration of the related receivables, we do not typically experience credit losses against our premium receivables and did not establish an allowance for credit loss at June 30, 2021 and December 31, 2020.</span></div><div style="text-align:justify;text-indent:36pt"><span><br/></span></div><div style="margin-bottom:9pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Premiums receivable may be written off prior to 120 days in the ordinary course of business for non-credit events including, but not limited to, the modification or refinancing of an underlying insured loan.</span></div><div style="margin-bottom:9pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> We establish a reserve for the write-off of premiums receivable based on historical experience. Our premium write-off reserve was not material at June 30, 2021 or December 31, 2020.</span></div>
	nmih	Premium Receivable Number Of Days To Be Written Off PremiumReceivableNumberOfDaysToBeWrittenOff	P120D
	nmih	Premium Receivable Number Of Days To Be Written Off PremiumReceivableNumberOfDaysToBeWrittenOff	P120D

Files In Submission

Name	View Source	Status
0001547903-21-000145-index-headers.html	Edgar Link	pending
0001547903-21-000145-index.html	Edgar Link	pending
0001547903-21-000145.txt	Edgar Link	pending
0001547903-21-000145-xbrl.zip	Edgar Link	pending
ex1020q32020joinderagreeme.htm	Edgar Link	pending
ex311q22021.htm	Edgar Link	pending
ex312q22021.htm	Edgar Link	pending
ex321q22021.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
nmih-20210630.htm	Edgar Link	pending
nmih-20210630.xsd	Edgar Link	pending
nmih-20210630_cal.xml	Edgar Link	unprocessable
nmih-20210630_def.xml	Edgar Link	unprocessable
nmih-20210630_htm.xml	Edgar Link	completed
nmih-20210630_lab.xml	Edgar Link	unprocessable
nmih-20210630_pre.xml	Edgar Link	unprocessable
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$NMIH
NMI Holdings, Inc. Stock $nmih

2021 Q2 Form 10-Q Financial Statement

#000154790321000145 Filed on August 04, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$NMIH NMI Holdings, Inc. Stock $nmih

2021 Q2 Form 10-Q Financial Statement

#000154790321000145 Filed on August 04, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$NMIH
NMI Holdings, Inc. Stock $nmih