Fair Value Measurements - Changes in Level 3 Financial Assets and Financial Liabilities Carried at Fair Value (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Transfers into/(out of) Level 3
Change in unrealized gains or losses included in Other comprehensive income (loss), net of tax for assets held at the end of the reporting period	$ (11)	$ 7	$ (25)	$ (9)
Debt and Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance		903		854
Balance	686		796
Total gains (losses) included in shareholders' net income	(2)	(1)	10	(11)
Gains (losses) included in other comprehensive income	(13)	7	(28)	(9)
Gains (losses) required to adjust future policy benefits for settlement annuities	(11)	1	(23)	(7)
Purchases, sales and settlements
Purchases	27	42	76	71
Settlements	(71)	(9)	(152)	(25)
Total purchases, sales and settlements	(44)	33	(76)	46
Transfers into/(out of) Level 3
Transfers into Level 3	17	37	118	123
Transfers out of Level 3	(121)	(126)	(285)	(142)
Total transfers into/(out of) Level 3	(104)	(89)	(167)	(19)
Balance		854		854
Balance	512		512
Total gains (losses) included in Shareholders' net income attributable to instruments held at the reporting date	$ (3)	$ (1)	$ (2)	$ (12)