Investments Schedule of Gains and Losses on Equity and Other Investments (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	$ 162	$ 160	$ (245)	$ 44
Equity Securities
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)	126	137	(23)	200
Less: Net gains (losses) recognized from sales of securities	46	32	140	20
Unrealized Gain (Loss) on Investments	80	105	(163)	180
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	98	61	90	21
Less: Net gains (losses) recognized from sales of securities	1	3	1	4
Unrealized Gain (Loss) on Investments	97	58	89	17
Private equities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	93	(28)	109	(17)
Less: Net gains (losses) recognized from sales of securities	0	0	0	0
Unrealized Gain (Loss) on Investments	93	(28)	109	(17)
Equity securities, Private equities and Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	317	170	176	204
Less: Net gains (losses) recognized from sales of securities	47	35	141	24
Unrealized Gain (Loss) on Investments	$ 270	$ 135	$ 35	$ 180

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
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-Section S99
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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