Investments - Fair Value and Gross Unrealized Losses in a Continuous Unrealized Loss Position (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2025 USD ($) security	Dec. 31, 2024 USD ($) security
Fair Value
Less Than or Equal to Twelve Months	$ 9,887	$ 21,106
Greater Than Twelve Months	38,455	35,528
Total	48,342	56,634
Gross Unrealized Losses
Less Than or Equal to Twelve Months	1,048	1,524
Greater Than Twelve Months	5,183	6,262
Total	$ 6,231	$ 7,786
Total number of fixed maturity AFS securities in an unrealized loss position | security	5,628	6,645
Unrealized holding losses arising during the period	$ 20	$ 23
Corporate bonds
Fair Value
Less Than or Equal to Twelve Months	7,540	16,388
Greater Than Twelve Months	31,661	29,045
Total	39,201	45,433
Gross Unrealized Losses
Less Than or Equal to Twelve Months	979	1,290
Greater Than Twelve Months	4,500	5,414
Total	5,479	6,704
U.S. government bonds
Fair Value
Less Than or Equal to Twelve Months	69	85
Greater Than Twelve Months	200	224
Total	269	309
Gross Unrealized Losses
Less Than or Equal to Twelve Months	6	3
Greater Than Twelve Months	25	37
Total	31	40
State and municipal bonds
Fair Value
Less Than or Equal to Twelve Months	172	652
Greater Than Twelve Months	927	721
Total	1,099	1,373
Gross Unrealized Losses
Less Than or Equal to Twelve Months	25	61
Greater Than Twelve Months	205	209
Total	230	270
Foreign government bonds
Fair Value
Less Than or Equal to Twelve Months	0	29
Greater Than Twelve Months	141	118
Total	141	147
Gross Unrealized Losses
Less Than or Equal to Twelve Months	0	5
Greater Than Twelve Months	50	51
Total	50	56
RMBS
Fair Value
Less Than or Equal to Twelve Months	227	658
Greater Than Twelve Months	817	724
Total	1,044	1,382
Gross Unrealized Losses
Less Than or Equal to Twelve Months	7	29
Greater Than Twelve Months	107	133
Total	114	162
CMBS
Fair Value
Less Than or Equal to Twelve Months	142	475
Greater Than Twelve Months	1,024	777
Total	1,166	1,252
Gross Unrealized Losses
Less Than or Equal to Twelve Months	2	29
Greater Than Twelve Months	91	106
Total	93	135
ABS
Fair Value
Less Than or Equal to Twelve Months	1,726	2,801
Greater Than Twelve Months	3,622	3,826
Total	5,348	6,627
Gross Unrealized Losses
Less Than or Equal to Twelve Months	28	106
Greater Than Twelve Months	199	303
Total	227	409
Hybrid and redeemable preferred securities
Fair Value
Less Than or Equal to Twelve Months	11	18
Greater Than Twelve Months	63	93
Total	74	111
Gross Unrealized Losses
Less Than or Equal to Twelve Months	1	1
Greater Than Twelve Months	6	9
Total	$ 7	$ 10