Investments (Changes in Net Unrealized Investment Gains (Losses)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Gain (Loss) on Securities [Line Items]
Unrealized investment gains (losses), beginning of year	$ (5,690)	$ 5,524	$ 5,761
Unrealized investment gains (losses) during the year	2,353	(16,766)	(3,478)
Unrealized investment gains (losses) relating to: Future policy benefits	(265)	2,572	671
Deferred income tax benefit (expense)	(438)	2,980	590
Unrealized investment gains (losses), end of year	(4,040)	(5,690)	5,524
Change in net unrealized investment gains (losses)	1,650	(11,214)	(2,217)
Cumulative effect of change in accounting principle, net of income tax
Gain (Loss) on Securities [Line Items]
Unrealized investment gains (losses), beginning of year	0	0	1,980
Unrealized investment gains (losses), end of year		0	0
Cumulative Effect, Adjusted Balance
Gain (Loss) on Securities [Line Items]
Unrealized investment gains (losses), beginning of year	$ (5,690)	5,524	7,741
Unrealized investment gains (losses), end of year		$ (5,690)	$ 5,524