Investments (Fixed Maturity Securities by Sector) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	$ 86,058	$ 86,565
Fixed maturity securities, allowance for credit losses	54	79	$ 25	$ 21
Fixed maturity securities, gross unrealized gains	673	491
Fixed maturity securities, gross unrealized losses	6,948	7,848
Fixed maturity securities, estimated fair value	79,729	79,129
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	40,340	40,437
Fixed maturity securities, allowance for credit losses	21	47	14	15
Fixed maturity securities, gross unrealized gains	288	212
Fixed maturity securities, gross unrealized losses	3,495	3,865
Fixed maturity securities, estimated fair value	37,112	36,737
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	12,840	13,203
Fixed maturity securities, allowance for credit losses	29	26	4	0
Fixed maturity securities, gross unrealized gains	74	53
Fixed maturity securities, gross unrealized losses	1,323	1,468
Fixed maturity securities, estimated fair value	11,562	11,762
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	8,214	8,056
Fixed maturity securities, allowance for credit losses	3	4	5	4
Fixed maturity securities, gross unrealized gains	58	45
Fixed maturity securities, gross unrealized losses	736	867
Fixed maturity securities, estimated fair value	7,533	7,230
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	7,076	7,112
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	105	39
Fixed maturity securities, gross unrealized losses	567	691
Fixed maturity securities, estimated fair value	6,614	6,460
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	6,165	6,348
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	26	33
Fixed maturity securities, gross unrealized losses	69	75
Fixed maturity securities, estimated fair value	6,122	6,306
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	6,692	6,702
Fixed maturity securities, allowance for credit losses	1	2	$ 2	$ 2
Fixed maturity securities, gross unrealized gains	6	7
Fixed maturity securities, gross unrealized losses	345	415
Fixed maturity securities, estimated fair value	6,352	6,292
State and political subdivision
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	3,711	3,671
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	86	78
Fixed maturity securities, gross unrealized losses	328	367
Fixed maturity securities, estimated fair value	3,469	3,382
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	1,020	1,036
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	30	24
Fixed maturity securities, gross unrealized losses	85	100
Fixed maturity securities, estimated fair value	$ 965	$ 960

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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