Investments - Gross Unrealized Appreciation (Depreciation) on Debt Securities (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 14,924	$ 15,775
Allowance for Credit Loss	(45)	(23)
Unrealized Appreciation	272	1,337
Unrealized Depreciation	(1,201)	(131)
Fair Value	13,950	16,958
Run-Off Settlement Annuity Business
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,266	2,262
Allowance for Credit Loss	(5)	(5)
Unrealized Appreciation	220	720
Unrealized Depreciation	(185)	(10)
Fair Value	2,296	2,967
Federal government and agency
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	303	287
Allowance for Credit Loss	0	0
Unrealized Appreciation	56	101
Unrealized Depreciation	(6)	(1)
Fair Value	353	387
State and local government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	157	154
Allowance for Credit Loss	0	0
Unrealized Appreciation	0	17
Unrealized Depreciation	(12)	0
Fair Value	145	171
Foreign government
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,471	2,468
Allowance for Credit Loss	0	0
Unrealized Appreciation	63	194
Unrealized Depreciation	(203)	(46)
Fair Value	2,331	2,616
Corporate
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,594	12,361
Allowance for Credit Loss	(45)	(23)
Unrealized Appreciation	151	1,008
Unrealized Depreciation	(946)	(80)
Fair Value	10,754	13,266
Mortgage and other asset-backed
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	399	505
Allowance for Credit Loss	0	0
Unrealized Appreciation	2	17
Unrealized Depreciation	(34)	(4)
Fair Value	$ 367	$ 518