Accumulated Other Comprehensive Income Loss - Reclassifications from AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net realized losses	$ (90)	$ (166)	$ (161)	$ (649)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	813	432	2,138	1,527
Income tax expense	162	92	405	300
Net Investment Income	597	487	1,652	1,537
Interest Expense	50	50	150	163
Net income	651	340	1,733	1,227
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income	(28)	(65)	(79)	(195)
Reclassification out of Accumulated Other Comprehensive Income | Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net realized losses	(26)	(70)	(74)	(222)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(26)	(70)	(74)	(222)
Income tax expense	(5)	(15)	(16)	(47)
Net income	(21)	(55)	(58)	(175)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	1	2	(2)	16
Income tax expense	0	0	0	0
Net income	1	2	(2)	16
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest rate swaps
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Investment Income	(5)	(1)	(20)	13
Interest Expense	4	0	11	(4)
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Currency Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Investment Income	2	3	7	7
Reclassification out of Accumulated Other Comprehensive Income | Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Insurance operating costs and other expenses	2	2	5	5
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Insurance operating costs and other expenses	(9)	(17)	(25)	(51)
Reclassification out of Accumulated Other Comprehensive Income | Pension and Other Postretirement Plan Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(7)	(15)	(20)	(46)
Income tax expense	(1)	(3)	(4)	(10)
Net income	(6)	$ (12)	(16)	$ (36)
Reclassification out of Accumulated Other Comprehensive Income | AOCI, Gain (Loss), Debt Securities, Available-for-sale, with Allowance for Credit Loss, Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net realized losses	(2)		(4)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(2)		(4)
Income tax expense	0		(1)
Net income	$ (2)		$ (3)