Investments (Details) - Net Unrealized Investment Gains (Losses) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Changes in net unrealized investment gains (losses) [Roll Forward]
Changes in net unrealized investment gains (losses)	$ (575)	$ 2,494	$ (9,640)
Income tax expense (benefit)	(79)	520	(2,002)
Change in net unrealized gains (losses) on investment securities, net of tax	(496)	1,974	(7,638)
Balance, beginning of year	(4,471)
Balance, end of year	(4,967)	(4,471)
Accumulated Other Comprehensive Income (Loss) [Member]
Changes in net unrealized investment gains (losses) [Roll Forward]
Changes in net unrealized investment gains (losses)	(575)	2,494	(9,640)
Income tax expense (benefit)	(79)	520	(2,002)
Change in net unrealized gains (losses) on investment securities, net of tax	(496)	1,974	(7,638)
Changes in Net Unrealized Gains (Losses) on Investment Securities [Member]
Changes in net unrealized investment gains (losses) [Roll Forward]
Changes in net unrealized investment gains (losses)	(639)	2,250	(9,280)
Income tax expense (benefit)	(128)	481	(1,967)
Change in net unrealized gains (losses) on investment securities, net of tax	(511)	1,769	(7,313)
Balance, beginning of year	(3,129)	(4,898)	2,415
Balance, end of year	(3,640)	(3,129)	(4,898)
Changes in Net Unrealized Gains (Losses) on Investment Securities [Member] | Fixed maturities [Member]
Changes in net unrealized investment gains (losses) [Roll Forward]
Changes in net unrealized investment gains (losses)	(640)	2,248	(9,279)
Changes in Net Unrealized Gains (Losses) on Investment Securities [Member] | Other investments [Member]
Changes in net unrealized investment gains (losses) [Roll Forward]
Changes in net unrealized investment gains (losses)	$ 1	$ 2	$ (1)