Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2025	Sep. 30, 2024
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	$ 77,551	$ 77,110	$ 75,730	$ 75,111	$ 74,150	$ 76,636	$ 75,730	$ 76,636
Other comprehensive income (loss)	144	213	179	528	22	(44)	536	506
Balance at end of period	73,110	77,551	77,110	75,106	75,111	74,150	73,110	75,106
Gains expected to be reclassified	16						16
AOCI Including Portion Attributable to Noncontrolling Interest
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	272		(120)	(319)		(297)	(120)	(297)
Balance at end of period	416	272		209	(319)		416	209
Net unrealized investment gains (losses):
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	4		(399)	(564)		(429)	(399)	(429)
Other comprehensive income (loss) before reclassifications, net of tax	175			647			498	382
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	17			32			97	162
Other comprehensive income (loss)	192			679			595	544
Balance at end of period	196	4		115	(564)		196	115
Other comprehensive income (loss) before reclassifications, pretax	209			710			533	427
Amounts reclassified from accumulated other comprehensive income (loss), pretax	19			36			106	184
Change in discount rate on long-duration insurance reserves:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	255		265	273		152	265	152
Other comprehensive income (loss) before reclassifications, net of tax	(50)			(147)			(60)	(26)
Other comprehensive income (loss)	(50)			(147)			(60)	(26)
Balance at end of period	205	255		126	273		205	126
Other comprehensive income (loss) before reclassifications, pretax	(65)			(189)			(77)	(33)
Foreign currency translation adjustments:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	0		(4)	0		0	(4)	0
Other comprehensive income (loss)	6			0			10	0
Balance at end of period	6	0		0	0		6	0
Net cash flow hedges:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	224		229	236		244	229	244
Other comprehensive income (loss) before reclassifications, net of tax	0			0			3	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(4)			(4)			(12)	(12)
Other comprehensive income (loss)	(4)			(4)			(9)	(12)
Balance at end of period	220	224		232	236		220	232
Other comprehensive income (loss) before reclassifications, pretax	0			0			5	0
Amounts reclassified from accumulated other comprehensive income (loss), pretax	(5)			(6)			(17)	(16)
Pension and other postretirement benefits:
Changes in Accumulated Other Comprehensive Income (Loss) by Component
Balance at beginning of period	(211)		$ (211)	(264)		$ (264)	(211)	(264)
Other comprehensive income (loss)	0			0			0	0
Balance at end of period	$ (211)	$ (211)		$ (264)	$ (264)		$ (211)	$ (264)