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Business and Basis of Presentation - Gain on Equity Method Investment (Details) - USD ($) $ in Millions |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jul. 01, 2023 | Sep. 30, 2024 | Dec. 31, 2023 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity method investments, fair value | $ 444 |  |  |  |  |
Gain on sale of asset management subsidiaries | 255 | $ 0 |  | $ 255 | $ 0 | $ 255
Sound Point Agreement |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Goodwill and intangible assets | 155 |  |  |  |  |
Sound Point Capital Management, LP |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity method investments, fair value | 419 |  |  |  |  |
Equity method investments |  | $ 417 | $ 429 |  | $ 417 |
Gain (loss) on sale of asset management subsidiaries | 248 |  | $ (7) |  |  |
Other consideration |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity method investments, fair value | 25 |  |  |  |  |
Managed by AssuredIM |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Equity method investments | 189 |  |  |  |  |
Assured Healthcare Partners LLC |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |
Gain (loss) on sale of asset management subsidiaries | $ 7 |  |  |  |  |

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- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 270 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482964/270-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (ee) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-32 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481664/323-10-45-1 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(10)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 25 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-25 + Details
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