Investments (Schedule of Gains and Losses on Equity and Other Investments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)		$ 117	$ (607)	$ (1,085)
Unrealized gains (losses) recognized for securities still held at reporting date		(361)	3,120	(9,535)
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)	[1]	194	(38)	(230)
Less: Net gains (losses) recognized from sales of securities		25	(68)	409
Unrealized gains (losses) recognized for securities still held at reporting date		169	30	(639)
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)	[1]	602	(12)	0
Less: Net gains (losses) recognized from sales of securities		4	0
Unrealized gains (losses) recognized for securities still held at reporting date		598	(12)
Private equities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)		124	70	(31)
Less: Net gains (losses) recognized from sales of securities		0	0	0
Unrealized gains (losses) recognized for securities still held at reporting date		124	70	(31)
Equity securities, Private equities and other investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)		920	20	(261)
Less: Net gains (losses) recognized from sales of securities		29	(68)	409
Unrealized gains (losses) recognized for securities still held at reporting date		$ 891	$ 88	$ (670)

[1] In 2024, Other investments - Fixed maturities and Equity securities includes $275 million and $(22) million, respectively, of realized gains (losses) related to investments measured under the fair value option.