Investments Schedule of Gains and Losses on Equity and Other Investments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	$ (116)	$ (101)
Equity Securities
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)	63	3
Less: Net gains (losses) recognized from sales of securities	(12)	(3)
Unrealized Gain (Loss) on Investments	75	6
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(40)	168
Less: Net gains (losses) recognized from sales of securities	1	0
Unrealized Gain (Loss) on Investments	(41)	168
Private equities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	11	31
Less: Net gains (losses) recognized from sales of securities	0	0
Unrealized Gain (Loss) on Investments	11	31
Equity securities, Private equities and Other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	34	202
Less: Net gains (losses) recognized from sales of securities	(11)	(3)
Unrealized Gain (Loss) on Investments	$ 45	$ 205

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
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 4
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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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-Section S99
-Paragraph 2
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-Publisher FASB
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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