Fair Value Measurements - Changes in Level 3 Financial Assets and Financial Liabilities Carried at Fair Value (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Transfers into/(out of) Level 3
Change in unrealized gains or losses included in Other comprehensive (loss), net of tax for assets held at the end of the reporting period	$ (13)	$ (16)
Debt and Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance		854
Balance	796
Total gains (losses) included in shareholders' net income	12	(10)
Gains (losses) included in other comprehensive income	(15)	(16)
Gains (losses) required to adjust future policy benefits for settlement annuities	(12)	(8)
Purchases, sales and settlements
Purchases	49	29
Settlements	(81)	(16)
Total purchases, sales and settlements	(32)	13
Transfers into/(out of) Level 3
Transfers into Level 3	101	86
Transfers out of Level 3	(164)	(16)
Total transfers into/(out of) Level 3	(63)	70
Balance		903
Balance	686
Total gains (losses) included in Shareholders' net income attributable to instruments held at the reporting date	$ 0	$ (11)

This element represents total gains or losses for the period (realized and unrealized), arising from assets included in income attributable to instruments held at the reporting date, measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in asset value.

No definition available.