Investments Schedule of Gains and Losses on Equity and Other Investments (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	$ (455)	$ 283	$ (700)	$ 327
Equity Securities
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)	(329)	396	(352)	596
Less: Net gains (losses) recognized from sales of securities	29	59	169	79
Unrealized Gain (Loss) on Investments	(358)	337	(521)	517
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(39)	82	51	103
Less: Net gains (losses) recognized from sales of securities	1	0	2	4
Unrealized Gain (Loss) on Investments	(40)	82	49	99
Private equities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(105)	48	4	31
Less: Net gains (losses) recognized from sales of securities	0	0	0	0
Unrealized Gain (Loss) on Investments	(105)	48	4	31
Equity securities, Private equities and Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(473)	526	(297)	730
Less: Net gains (losses) recognized from sales of securities	30	59	171	83
Unrealized Gain (Loss) on Investments	$ (503)	$ 467	$ (468)	$ 647

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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-Name Accounting Standards Codification
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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
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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