Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	$ 75,730	$ 76,636
Other comprehensive income (loss)	179	(44)
Balance at end of period	77,110	74,150
Gains expected to be reclassified	16
AOCI Including Portion Attributable to Noncontrolling Interest
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(120)	(297)
Balance at end of period	59	(341)
Net unrealized investment losses:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(399)	(429)
Other comprehensive income (loss) before reclassifications, net of tax	187	(156)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	29	48
Other comprehensive income (loss)	216	(108)
Balance at end of period	(183)	(537)
Other comprehensive income (loss) before reclassifications, pretax	188	(162)
Amounts reclassified from accumulated other comprehensive income (loss), pretax	32	54
Change in discount rate on long-duration insurance reserves:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	265	152
Other comprehensive income (loss) before reclassifications, net of tax	(33)	68
Other comprehensive income (loss)	(33)	68
Balance at end of period	232	220
Other comprehensive income (loss) before reclassifications, pretax	(41)	88
Foreign currency translation adjustments:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(4)	0
Other comprehensive income (loss)	0	0
Balance at end of period	(4)	0
Net cash flow hedges:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	229	244
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(4)	(4)
Other comprehensive income (loss)	(4)	(4)
Balance at end of period	225	240
Amounts reclassified from accumulated other comprehensive income (loss), pretax	(6)	(6)
Pension and other postretirement benefits:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(211)	(264)
Other comprehensive income (loss)	0	0
Balance at end of period	$ (211)	$ (264)