Investments (Schedule of Gains and Losses on Equity and Other Investments) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	$ (965)	$ 1,152	$ (498)
Unrealized gains (losses) recognized for securities still held at reporting date	(9,535)	(2,417)	2,130
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)	(230)	662	586
Less: Net gains recognized from sales of securities	409	157	455
Unrealized gains (losses) recognized for securities still held at reporting date	(639)	505	131
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(31)	111	(32)
Less: Net gains recognized from sales of securities	0	0	0
Unrealized gains (losses) recognized for securities still held at reporting date	(31)	111	(32)
Equity securities and other investments [Member]
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	(261)	773	554
Less: Net gains recognized from sales of securities	409	157	455
Unrealized gains (losses) recognized for securities still held at reporting date	$ (670)	$ 616	$ 99

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/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117546-209714

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(d))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

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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.

+ References

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-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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