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Schedule I - Investments (Detail) $ in Millions | Dec. 31, 2024 USD ($)
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Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | $ 1,855
Fair Value | 1,655
Amount at which shown in the balance sheet | 1,655
Other Investments [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 1
Fair Value | 1
Amount at which shown in the balance sheet | 1
Assets Of Consolidated VIEs [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 37
Fair Value | 28
Amount at which shown in the balance sheet | 28
Loans Receivable [Member] | Assets Of Consolidated VIEs [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 37
Fair Value | 28
Amount at which shown in the balance sheet | 28
Long-Term Available-For-Sale [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 1,080
Fair Value | 925
Amount at which shown in the balance sheet | 925
Long-Term Available-For-Sale [Member] | U.S. Treasury And Government Agency [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 189
Fair Value | 170
Amount at which shown in the balance sheet | 170
Long-Term Available-For-Sale [Member] | US States And Political Subdivisions [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 110
Fair Value | 101
Amount at which shown in the balance sheet | 101
Long-Term Available-For-Sale [Member] | Foreign Governments [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 12
Fair Value | 10
Amount at which shown in the balance sheet | 10
Long-Term Available-For-Sale [Member] | Corporate Obligations [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 496
Fair Value | 391
Amount at which shown in the balance sheet | 391
Short-Term Available-For-Sale [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 311
Fair Value | 311
Amount at which shown in the balance sheet | 311
AFS Investments [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 1,391
Fair Value | 1,236
Amount at which shown in the balance sheet | 1,236
Investments At Fair Value [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 463
Fair Value | 418
Amount at which shown in the balance sheet | 418
Mortgage-backed [Member] | Long-Term Available-For-Sale [Member] | Residential Mortgage backed Agency [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 127
Fair Value | 111
Amount at which shown in the balance sheet | 111
Mortgage-backed [Member] | Long-Term Available-For-Sale [Member] | Residential Mortgage-Backed Non Agency [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 36
Fair Value | 32
Amount at which shown in the balance sheet | 32
Mortgage-backed [Member] | Long-Term Available-For-Sale [Member] | Commercial Mortgage-Backed [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 7
Fair Value | 7
Amount at which shown in the balance sheet | 7
Asset-backed [Member] | Long-Term Available-For-Sale [Member] | Collateralized Debt Obligations [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 71
Fair Value | 72
Amount at which shown in the balance sheet | 72
Asset-backed [Member] | Long-Term Available-For-Sale [Member] | Other Asset-Backed [Member] |
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items] |
Cost | 32
Fair Value | 31
Amount at which shown in the balance sheet | $ 31

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