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Investments - Summary of Gross Unrealized Losses and Fair Values of Ambac's Available-for-Sale Investments (Detail) (Successor [Member], USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
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Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | $ 1,133,155 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue | $ 1,324,489 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Less than 12 Months, Gross Unrealized Loss | 22,671 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss | 20,081 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 239,992 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue | 350,655 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 6,692 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss | 12,188 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,373,147 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue | 1,675,144 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 29,363 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax | 32,269 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Municipal Bonds [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 77,788 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 1,244 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 135,076 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 5,752 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Corporate Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 453,504 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 4,998 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 172,045 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 4,418 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Foreign Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 20,827 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 748 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 14,277 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 596 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 7,223 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 154 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 14,735 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 273 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
U.S. Agency Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 25,039 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 2 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 4,378 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 36 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Residential Mortgage-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 413,203 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 12,391 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 10,076 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 1,109 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Collateralized Debt Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 5,012 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 274 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Other Asset-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value |  | 248,823 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss |  | 155 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  | 68 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments |  | 4 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Short-Term [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 8,803 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 4 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 8,803 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 0 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 4 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Investments And Other Investments [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 1,133,155 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,260,222 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 22,671 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 19,970 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 239,992 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 350,655 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 6,692 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 12,188 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,373,147 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,610,877 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 29,363 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 32,158 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 1,133,155 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,251,419 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 22,671 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 19,966 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 239,992 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 350,655 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 6,692 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 12,188 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,373,147 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,602,074 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 29,363 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 32,154 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Municipal Bonds [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 46,461 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 412 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 119,412 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 3,792 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 165,873 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 212,864 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 4,204 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 6,996 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Corporate Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 278,044 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 2,081 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 81,739 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 1,209 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 359,783 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 625,549 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 3,290 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 9,416 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Foreign Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 32,206 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 1,864 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 8,900 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 611 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 41,106 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 35,104 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 1,661 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 2 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 10,814 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 102 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 12,475 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 21,958 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 104 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 427 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | U.S. Agency Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 4,359 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 11 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 4,359 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 29,417 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 11 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 38 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Residential Mortgage-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 547,706 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 17,336 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 10,266 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 821 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 557,972 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 423,279 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 18,157 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 13,500 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Collateralized Debt Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 63,834 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 289 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 4,434 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 144 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 68,268 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 5,012 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 433 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 274 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Other Asset-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 163,243 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 687 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 68 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 2 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 163,311 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 248,891 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 689 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 159 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed Income Securities [Member] | Foreign Government Debt Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 2,475 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,344 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Securities Pledged as Collateral [Member] | Fixed Income Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 111 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 0 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 111 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Securities Pledged as Collateral [Member] | Fixed Income Securities [Member] | U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 111 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 0 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 111 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Securities Pledged as Collateral [Member] | Securities Pledged as Collateral [Member] | U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | $ 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | $ 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember

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