Closed Block (Liabilities and Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Closed Block Liabilities
Future policy benefits	$ 38,373	$ 38,758
Other policy-related balances	271	321
Policyholder dividends payable	340	337
Policyholder dividend obligation	2,115	2,969	$ 2,020
Deferred income tax liability	161	130
Other liabilities	276	172
Total closed block liabilities	41,536	42,687
Assets Designated to the Closed Block
Fixed maturity securities available-for-sale, at estimated fair value	26,320	27,186
Equity securities, at estimated fair value	22	24
Mortgage loans	6,447	6,807
Policy loans	4,272	4,355
Real estate and real estate joint ventures	551	559
Other invested assets	484	468
Total investments	38,096	39,399
Cash and cash equivalents	199	0
Accrued investment income	386	402
Premiums, reinsurance and other receivables	52	50
Current income tax recoverable	46	28
Total assets designated to the closed block	38,779	39,879
Excess of closed block liabilities over assets designated to the closed block	2,757	2,808
AOCI:
Unrealized investment gains (losses), net of income tax	2,911	3,524
Unrealized gains (losses) on derivatives, net of income tax	47	23
Allocated to policyholder dividend obligation, net of income tax	(1,671)	(2,346)
Total amounts included in AOCI	1,287	1,201
Maximum future earnings to be recognized from closed block assets and liabilities	$ 4,044	$ 4,009