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	$ 19,634	$ 30,166
Greater Than Twelve Months	39,228	36,345
Total	58,862	66,511
Gross Unrealized Losses
Less Than or Equal to Twelve Months	3,584	4,537
Greater Than Twelve Months	5,387	6,468
Total	$ 8,971	$ 11,005
Total number of fixed maturity AFS securities in an unrealized loss position | security	5,999	6,985
Unrealized holding losses arising during the period	$ 20	$ 23
Corporate bonds
Fair Value
Less Than or Equal to Twelve Months	16,303	24,657
Greater Than Twelve Months	32,356	29,786
Total	48,659	54,443
Gross Unrealized Losses
Less Than or Equal to Twelve Months	3,308	4,054
Greater Than Twelve Months	4,680	5,601
Total	7,988	9,655
U.S. government bonds
Fair Value
Less Than or Equal to Twelve Months	69	86
Greater Than Twelve Months	200	224
Total	269	310
Gross Unrealized Losses
Less Than or Equal to Twelve Months	6	3
Greater Than Twelve Months	25	38
Total	31	41
State and municipal bonds
Fair Value
Less Than or Equal to Twelve Months	689	1,087
Greater Than Twelve Months	970	760
Total	1,659	1,847
Gross Unrealized Losses
Less Than or Equal to Twelve Months	176	228
Greater Than Twelve Months	215	217
Total	391	445
Foreign government bonds
Fair Value
Less Than or Equal to Twelve Months	4	32
Greater Than Twelve Months	141	118
Total	145	150
Gross Unrealized Losses
Less Than or Equal to Twelve Months	1	5
Greater Than Twelve Months	50	51
Total	51	56
RMBS
Fair Value
Less Than or Equal to Twelve Months	405	795
Greater Than Twelve Months	851	760
Total	1,256	1,555
Gross Unrealized Losses
Less Than or Equal to Twelve Months	40	76
Greater Than Twelve Months	121	144
Total	161	220
CMBS
Fair Value
Less Than or Equal to Twelve Months	317	579
Greater Than Twelve Months	1,024	777
Total	1,341	1,356
Gross Unrealized Losses
Less Than or Equal to Twelve Months	16	50
Greater Than Twelve Months	91	106
Total	107	156
ABS
Fair Value
Less Than or Equal to Twelve Months	1,831	2,907
Greater Than Twelve Months	3,623	3,827
Total	5,454	6,734
Gross Unrealized Losses
Less Than or Equal to Twelve Months	35	118
Greater Than Twelve Months	199	303
Total	234	421
Hybrid and redeemable preferred securities
Fair Value
Less Than or Equal to Twelve Months	16	23
Greater Than Twelve Months	63	93
Total	79	116
Gross Unrealized Losses
Less Than or Equal to Twelve Months	2	3
Greater Than Twelve Months	6	8
Total	$ 8	$ 11