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Fair Value of Financial Instruments (Company's Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail) - Fair Value Measurements Recurring [Member] - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | $ 2,000 |  | $ 2,094
Fair value financial liabilities measured on recurring basis | 98 |  | 134
Money Market Securities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 85 |  | 34
Medium-term Notes [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 36 |  | 40
Equity investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 153 |  | 155
Cash and Cash Equivalents [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 131 |  | 104
Fixed Maturities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1,565 |  | 1,739
Fixed Maturities [Member] | U.S. Treasury And Government Agency [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 553 |  | 712
Fixed Maturities [Member] | State and municipal bonds [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 119 |  | 123
Fixed Maturities [Member] | Foreign Government Debt [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 13 |  | 18
Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 497 |  | 497
Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 140 |  | 149
Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 34 |  | 34
Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 14 |  | 14
Fixed Maturities [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 132 |  | 146
Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 63 |  | 46
Assets Of Consolidated V I Es [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 10 |  | 10
Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 10 |  | 10
Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1 |  | 1
Assets Of Consolidated V I Es [Member] | Other Asset Backed [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1 |  | 1
Assets Of Consolidated V I Es [Member] | Loans Receivable and Other Instruments At Fair Value [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Residential Loans Receivable [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 36 |  | 35
Assets Of Consolidated V I Es [Member] | Cash and Cash Equivalents [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 6 |  | 3
Assets Of Consolidated V I Es [Member] | Other [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 2 |  | 2
Other Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 1 |  | 1
Other Liabilities [Member] | Interest rate derivatives [Member] | Non-insured interest rate derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis |  |  | 1
Liabilities Of Consolidated Vies [Member] | Currency Derivatives [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 15 |  | 14
Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 46 |  | 78
Fair Value Inputs Level 1 [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 811 |  | 885
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Money Market Securities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 85 |  | 34
Fair Value Inputs Level 1 [Member] | Medium-term Notes [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Equity investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 43 |  | 39
Fair Value Inputs Level 1 [Member] | Cash and Cash Equivalents [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 131 |  | 104
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 546 |  | 705
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | U.S. Treasury And Government Agency [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 546 |  | 705
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | State and municipal bonds [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Foreign Government Debt [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Other Asset Backed [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Loans Receivable and Other Instruments At Fair Value [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Residential Loans Receivable [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Cash and Cash Equivalents [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 6 |  | 3
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Other [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Other Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Other Liabilities [Member] | Interest rate derivatives [Member] | Non-insured interest rate derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis |  |  | 0
Fair Value Inputs Level 1 [Member] | Liabilities Of Consolidated Vies [Member] | Currency Derivatives [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 1 [Member] | Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1,042 |  | 1,063
Fair value financial liabilities measured on recurring basis | 1 |  | 2
Fair Value Inputs Level 2 [Member] | Money Market Securities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Medium-term Notes [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Equity investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 8 |  | 8
Fair Value Inputs Level 2 [Member] | Cash and Cash Equivalents [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1,012 |  | 1,033
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | U.S. Treasury And Government Agency [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 7 |  | 7
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | State and municipal bonds [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 119 |  | 123
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Foreign Government Debt [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 13 |  | 18
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 490 |  | 496
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 140 |  | 149
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 34 |  | 34
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 14 |  | 14
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 132 |  | 146
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 63 |  | 46
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 10 |  | 10
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 10 |  | 10
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1 |  | 1
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Other Asset Backed [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 1 |  | 1
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Loans Receivable and Other Instruments At Fair Value [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Residential Loans Receivable [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Cash and Cash Equivalents [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Other [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Other Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 1 |  | 1
Fair Value Inputs Level 2 [Member] | Other Liabilities [Member] | Interest rate derivatives [Member] | Non-insured interest rate derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis |  |  | 1
Fair Value Inputs Level 2 [Member] | Liabilities Of Consolidated Vies [Member] | Currency Derivatives [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 2 [Member] | Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 147 |  | 146
Fair value financial liabilities measured on recurring basis | 97 |  | 132
Fair Value Inputs Level 3 [Member] | Money Market Securities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Medium-term Notes [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 36 |  | 40
Fair Value Inputs Level 3 [Member] | Equity investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 102 |  | 108
Fair Value Inputs Level 3 [Member] | Cash and Cash Equivalents [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 7 |  | 1
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | U.S. Treasury And Government Agency [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | State and municipal bonds [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Foreign Government Debt [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 7 | [1] | 1
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Other Asset Backed [Member] | Asset-backed [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Loans Receivable and Other Instruments At Fair Value [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Residential Loans Receivable [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 36 |  | 35
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Cash and Cash Equivalents [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Other [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial assets measured on recurring basis | 2 |  | 2
Fair Value Inputs Level 3 [Member] | Other Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 0 |  | 0
Fair Value Inputs Level 3 [Member] | Other Liabilities [Member] | Interest rate derivatives [Member] | Non-insured interest rate derivatives [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis |  |  | 0
Fair Value Inputs Level 3 [Member] | Liabilities Of Consolidated Vies [Member] | Currency Derivatives [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | 15 |  | 14
Fair Value Inputs Level 3 [Member] | Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity, Primary Beneficiary [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Fair value financial liabilities measured on recurring basis | $ 46 |  | $ 78
[1] | Includes loans carried at fair value of $6 million.

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
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