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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 | Dec. 31, 2014 | Dec. 31, 2013
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Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | $ 1,324,489 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue | $ 2,920,966 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Less than 12 Months, Gross Unrealized Loss | 20,081 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss | 116,634 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 350,655 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue |
Available For Sale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses Accumulated In Investments | 12,188 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,675,144 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 32,269 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax | 116,634 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Short-Term [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 8,803 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 4 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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_DebtSecurityAxis = 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_DebtSecurityAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 8,803 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 4 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_DebtSecurityAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 1,251,419 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,920,966 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Less than 12 Months, Gross Unrealized Loss | 19,966 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 116,634 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 350,655 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 12,188 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 77,788 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 437,683 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 28,427 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 135,076 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 5,752 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 453,504 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 877,356 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 23,894 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 172,045 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 4,418 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 20,827 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 117,905 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 6,901 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 14,277 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 596 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 7,223 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 70,044 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,176 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 14,735 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 273 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 25,039 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 5,834 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 70 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 4,378 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 36 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 413,203 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 644,502 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 18,105 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 10,076 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 1,109 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 5,012 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 137,685 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 463 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = 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 | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = 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 | 248,823 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 629,957 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 36,598 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = 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_DebtSecurityAxis = 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 | 4 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / 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 | 1,260,222 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 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 | 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 | 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 | 1,610,877 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 32,158 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = ambc_FixedIncomeInvestmentsAndOtherInvestmentsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 116,634 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 32,154 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 116,634 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 6,996 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 28,427 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 9,416 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 23,894 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] | U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 427 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,176 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 38 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 70 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 13,500 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 18,105 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 274 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 463 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 159 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 36,598 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] | Fixed Income Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 1,602,074 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | Municipal Bonds [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 212,864 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MunicipalBondsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | Corporate Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 625,549 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | Foreign Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 35,104 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 21,958 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | U.S. Agency Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 29,417 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | Residential Mortgage-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 423,279 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | Collateralized Debt Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 5,012 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Fixed Income Securities [Member] | Fixed Income Securities [Member] | Other Asset-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 248,891 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Securities Pledged as Collateral [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Less than 12 Months, Fair Value | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 111 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / 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_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_StatementScenarioAxis = us-gaap_SuccessorMember |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / 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 | 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Less than 12 Months, Gross Unrealized Loss | 111 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / 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 | 0 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / 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_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Securities Pledged as Collateral [Member] | Fixed Income Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 111 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 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] |  |
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments | 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 | 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
Securities Pledged as Collateral [Member] | Fixed Income Securities [Member] | Fixed Income Securities [Member] | U.S. Government Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | $ 64,267 us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue / us-gaap_DebtSecurityAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_FinancialInstrumentAxis = us-gaap_SecuritiesPledgedAsCollateralMember / us-gaap_InvestmentTypeAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |

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