Separate Account Assets and Liabilities - Separate account liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Separate Account, Liability [Roll Forward]
Balance, beginning of year	$ 84,853	$ 109,111
Premiums and deposits	2,224	3,235
Policy charges	(1,403)	(1,457)
Surrenders and withdrawals	(5,455)	(4,484)
Benefit payments	(1,080)	(1,112)
Investment performance	5,521	(23,851)
Net transfers from (to) general account and other	64	(140)
Balance, end of period	84,724	81,302
Cash surrender value	83,474	80,042
Individual Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	45,178	57,927
Premiums and deposits	1,124	1,905
Policy charges	(964)	(988)
Surrenders and withdrawals	(2,728)	(2,492)
Benefit payments	(640)	(684)
Investment performance	2,470	(12,440)
Net transfers from (to) general account and other	173	157
Balance, end of period	44,613	43,385
Cash surrender value	43,566	42,313
Group Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	34,361	45,138
Premiums and deposits	1,033	1,248
Policy charges	(333)	(356)
Surrenders and withdrawals	(2,205)	(1,931)
Benefit payments	(374)	(407)
Investment performance	2,806	(10,831)
Net transfers from (to) general account and other	(122)	(333)
Balance, end of period	35,166	32,528
Cash surrender value	34,980	32,340
Life Insurance
Separate Account, Liability [Roll Forward]
Balance, beginning of year	799	1,044
Premiums and deposits	27	28
Policy charges	(37)	(38)
Surrenders and withdrawals	(19)	(19)
Benefit payments	(5)	(5)
Investment performance	85	(252)
Net transfers from (to) general account and other	(2)	(1)
Balance, end of period	848	757
Cash surrender value	828	756
Institutional Markets
Separate Account, Liability [Roll Forward]
Balance, beginning of year	4,515	5,002
Premiums and deposits	40	54
Policy charges	(69)	(75)
Surrenders and withdrawals	(503)	(42)
Benefit payments	(61)	(16)
Investment performance	160	(328)
Net transfers from (to) general account and other	15	37
Balance, end of period	4,097	4,632
Cash surrender value	$ 4,100	$ 4,633