Accumulated Other Comprehensive Income Loss - Reclassifications from AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	$ 672	$ 554	$ 1,325	$ 1,095
Net Investment Income	540	541	1,055	1,050
Interest Expense	50	51	100	113
Income tax expense	125	110	243	208
Net income	547	444	1,082	887
Net realized losses	(64)	(338)	(71)	(483)
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income	(24)	(59)	(51)	(133)
Reclassification out of Accumulated Other Comprehensive Income | Net Unrealized Gain on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(21)	(65)	(48)	(152)
Income tax expense	(4)	(14)	(10)	(32)
Net income	(17)	(51)	(38)	(120)
Net realized losses	(21)	(65)	(48)	(152)
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	0	6	(3)	14
Income tax expense	0	1	(1)	3
Net income	0	5	(2)	11
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent | Interest rate swaps [1]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Investment Income	(7)	5	(15)	14
Interest Expense	4	(1)	7	(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	3	2	5	4
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	1	1	3	3
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Insurance operating costs and other expenses	(8)	(17)	(16)	(34)
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)	(16)	(13)	(31)
Income tax expense	(1)	(3)	(3)	(7)
Net income	(6)	$ (13)	(10)	$ (24)
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]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	(2)		(2)
Income tax expense	(1)		(1)
Net income	(1)		(1)
Net realized losses	$ (2)		$ (2)