Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	$ 74,150	$ 76,636	$ 71,580	$ 71,769	$ 76,636	$ 71,769
Other comprehensive income (loss)	22	(44)	17	389	(22)	406
Balance at end of period	75,111	74,150	73,002	71,580	75,111	73,002
AOCI Including Portion Attributable to Noncontrolling Interest
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(341)	(297)	(875)	(1,264)	(297)	(1,264)
Balance at end of period	(319)	(341)	(858)	(875)	(319)	(858)
Net unrealized investment losses:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(537)	(429)	(1,049)	(1,519)	(429)	(1,519)
Other comprehensive income (loss) before reclassifications, net of tax	(109)		(174)		(265)	165
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	82		110		130	241
Other comprehensive income (loss)	(27)		(64)		(135)	406
Balance at end of period	(564)	(537)	(1,113)	(1,049)	(564)	(1,113)
Other comprehensive income (loss) before reclassifications, pretax	(121)		(175)		(283)	165
Amounts reclassified from accumulated other comprehensive income (loss), pretax	94		110		148	241
Change in discount rate on long-duration insurance reserves:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	220	152	145	219	152	219
Other comprehensive income (loss) before reclassifications, net of tax	53		60		121	(14)
Other comprehensive income (loss)	53		60		121	(14)
Balance at end of period	273	220	205	145	273	205
Other comprehensive income (loss) before reclassifications, pretax	68		78		156	(23)
Foreign currency translation adjustments:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	0	0	(1)	0	0	0
Other comprehensive income (loss) before reclassifications, net of tax	0		2		0	0
Other comprehensive income (loss)	0		2		0	1
Balance at end of period	0	0	1	(1)	0	1
Net cash flow hedges:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	240	244	233	239	244	239
Other comprehensive income (loss) before reclassifications, net of tax	0		2		0	(2)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(4)		17		(8)	15
Other comprehensive income (loss)	(4)		19		(8)	13
Balance at end of period	236	240	252	233	236	252
Other comprehensive income (loss) before reclassifications, pretax	0		3		0	(3)
Amounts reclassified from accumulated other comprehensive income (loss), pretax	(5)		23		(11)	20
Gains expected to be reclassified	22				22
Pension and other postretirement benefits:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(264)	(264)	(203)	(203)	(264)	(203)
Other comprehensive income (loss)	0		0		0	0
Balance at end of period	$ (264)	$ (264)	$ (203)	$ (203)	$ (264)	$ (203)