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Schedule I - Summary Of Investments (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Dec. 31, 2021
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SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties, Cost | $ 2,630 |
Investments | 2,593 |
Available-for-sale Securities, Amortized Cost Basis | 2,041 | $ 2,140
Other Investments | 568 | 690
Available-for-sale Securities | 1,966 |
Investments | 2,593 | 2,955
Short-term Investments [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 507 | 415
Available-for-sale Securities | 507 | 414
ShortTermInvestmentsMember, including Pledged |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 572 |
Available-for-sale Securities | 572 |
Other Investments [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 528 |
Available-for-sale Securities | 556 |
Other Investments [Member] | Fixed Income Funds |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities | 568 |
Available-for-sale Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 60 |
Available-for-sale Securities | 59 |
Fixed Income Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 1,469 | 1,605
Available-for-sale Securities | 1,395 | 1,730
Fixed Income Securities [Member] | Municipal Bonds [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 44 | 315
Available-for-sale Securities | 43 | 340
Fixed Income Securities [Member] | Corporate Debt Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 659 | 612
Available-for-sale Securities | 598 | 613
Fixed Income Securities [Member] | Debt Security, Government, Non-US [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 85 | 89
Available-for-sale Securities | 76 | 87
Fixed Income Securities [Member] | Residential Mortgage-Backed Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 230 | 182
Available-for-sale Securities | 238 | 252
Fixed Income Securities [Member] | Collateralized Debt Obligations [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 141 | 128
Available-for-sale Securities | 137 | 128
Fixed Income Securities [Member] | Asset-backed Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 227 | 234
Available-for-sale Securities | 224 | 265
Fixed Income Securities [Member] | U S Government Obligations [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 68 |
Available-for-sale Securities | 65 |
Fixed Income Securities [Member] | US Government Debt Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 68 | 45
Available-for-sale Securities | 65 | $ 45
Fixed Income Securities [Member] | Corporate Obligations, Excluding Related Party Investments |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 659 |
Available-for-sale Securities | 598 |
Fixed Income Securities [Member] | Commercial Mortgage Backed Securities [Member] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Available-for-sale Securities, Amortized Cost Basis | 15 |
Available-for-sale Securities | 15 |
Fair Value Amount, Excluding Related Party Investments [Domain] |  |
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] |  |
Investments | $ 2,581 |

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