Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	$ 75,111	$ 74,150	$ 76,636	$ 73,002	$ 71,580	$ 71,769	$ 76,636	$ 71,769
Other comprehensive income (loss)	528	22	(44)	(146)	17	389	506	260
Balance at end of period	75,106	75,111	74,150	74,510	73,002	71,580	75,106	74,510
AOCI Including Portion Attributable to Noncontrolling Interest
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(319)		(297)	(858)		(1,264)	(297)	(1,264)
Balance at end of period	209	(319)		(1,004)	(858)		209	(1,004)
Net unrealized investment gains (losses):
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(564)		(429)	(1,113)		(1,519)	(429)	(1,519)
Other comprehensive income (loss) before reclassifications, net of tax	647			(478)			382	(313)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	32			157			162	398
Other comprehensive income (loss)	679			(321)			544	85
Balance at end of period	115	(564)		(1,434)	(1,113)		115	(1,434)
Other comprehensive income (loss) before reclassifications, pretax	710			(475)			427	(310)
Amounts reclassified from accumulated other comprehensive income (loss), pretax	36			157			184	398
Change in discount rate on long-duration insurance reserves:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	273		152	205		219	152	219
Other comprehensive income (loss) before reclassifications, net of tax	(147)			181			(26)	167
Other comprehensive income (loss)	(147)			181			(26)	167
Balance at end of period	126	273		386	205		126	386
Other comprehensive income (loss) before reclassifications, pretax	(189)			233			(33)	210
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	(1)
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	236		244	252		239	244	239
Other comprehensive income (loss) before reclassifications, net of tax	0			0			0	19
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(4)			(4)			(12)	(10)
Other comprehensive income (loss)	(4)			(4)			(12)	9
Balance at end of period	232	236		248	252		232	248
Other comprehensive income (loss) before reclassifications, pretax	0			0			0	25
Amounts reclassified from accumulated other comprehensive income (loss), pretax	(6)			(5)			(16)	(13)
Gains expected to be reclassified	16						16
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)