Investments Schedule of Gains and Losses on Equity and Other Investments (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	$ 160	$ 104	$ 44	$ 3
Equity Securities
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)	137	21	200	24
Less: Net gains (losses) recognized from sales of securities	32	14	20	11
Unrealized Gain (Loss) on Investments	105	7	180	13
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	61	132	21	300
Less: Net gains (losses) recognized from sales of securities	3	0	4	0
Unrealized Gain (Loss) on Investments	58	132	17	300
Private equities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(28)	49	(17)	80
Less: Net gains (losses) recognized from sales of securities	0	0	0	0
Unrealized Gain (Loss) on Investments	(28)	49	(17)	80
Equity securities, Private equities and Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	170	202	204	404
Less: Net gains (losses) recognized from sales of securities	35	14	24	11
Unrealized Gain (Loss) on Investments	$ 135	$ 188	$ 180	$ 393

Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 321
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The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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