Closed Block (Liabilities and Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Closed Block Liabilities
Future policy benefits	$ 37,787	$ 38,046
Other policy-related balances	312	290
Policyholder dividends payable	249	253
Policyholder dividend obligation	0	1,682	$ 2,969
Deferred income tax liability	146	210
Other liabilities	337	263
Total closed block liabilities	38,831	40,744
Assets Designated to the Closed Block
Fixed maturity securities available-for-sale, at estimated fair value	23,412	25,669
Equity securities, at estimated fair value	14	21
Mortgage loans	6,462	6,417
Policy loans	4,149	4,191
Real estate and real estate joint ventures	547	565
Other invested assets	551	535
Total investments	35,135	37,398
Cash and cash equivalents	203	126
Accrued investment income	389	384
Premiums, reinsurance and other receivables	38	50
Current income tax recoverable	89	81
Total assets designated to the closed block	35,854	38,039
Excess of closed block liabilities over assets designated to the closed block	2,977	2,705
AOCI:
Unrealized investment gains (losses), net of income tax	970	2,562
Unrealized gains (losses) on derivatives, net of income tax	123	107
Allocated to policyholder dividend obligation, net of income tax	0	(1,329)
Total amounts included in AOCI	1,093	1,340
Maximum future earnings to be recognized from closed block assets and liabilities	$ 4,070	$ 4,045