Separate Account Assets and Liabilities - Separate account liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Separate Account, Liability [Roll Forward]
Balance, beginning of year	$ 84,853
Balance, end of year	91,005	$ 84,853
Life and Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	84,853	109,111	$ 100,290
Premiums and deposits	2,859	4,137	6,185
Policy charges	(1,824)	(1,937)	(2,041)
Surrenders and withdrawals	(7,537)	(5,925)	(7,388)
Benefit payments	(1,476)	(1,576)	(1,687)
Investment performance	14,067	(18,860)	14,120
Net transfers from (to) general account and other	63	(97)	(368)
Balance, end of year	91,005	84,853	109,111
Cash surrender value	89,808	83,588	107,655
Life and Retirement | Individual Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	45,178	57,927	53,456
Premiums and deposits	1,408	2,420	4,081
Policy charges	(1,241)	(1,325)	(1,368)
Surrenders and withdrawals	(3,744)	(3,320)	(4,261)
Benefit payments	(844)	(898)	(1,039)
Investment performance	6,933	(9,861)	6,743
Net transfers from (to) general account and other	203	235	315
Balance, end of year	47,893	45,178	57,927
Cash surrender value	46,911	44,124	56,727
Life and Retirement | Group Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	34,361	45,138	41,310
Premiums and deposits	1,374	1,611	1,979
Policy charges	(441)	(461)	(523)
Surrenders and withdrawals	(3,047)	(2,452)	(3,013)
Benefit payments	(557)	(613)	(615)
Investment performance	6,666	(8,479)	6,711
Net transfers from (to) general account and other	(168)	(383)	(711)
Balance, end of year	38,188	34,361	45,138
Cash surrender value	37,992	34,169	44,909
Life and Retirement | Life Insurance
Separate Account, Liability [Roll Forward]
Balance, beginning of year	799	1,044	912
Premiums and deposits	36	37	49
Policy charges	(49)	(51)	(52)
Surrenders and withdrawals	(25)	(22)	(32)
Benefit payments	(7)	(6)	(10)
Investment performance	181	(201)	180
Net transfers from (to) general account and other	(3)	(2)	(3)
Balance, end of year	932	799	1,044
Cash surrender value	911	777	1,026
Life and Retirement | Institutional Markets
Separate Account, Liability [Roll Forward]
Balance, beginning of year	4,515	5,002	4,612
Premiums and deposits	41	69	76
Policy charges	(93)	(100)	(98)
Surrenders and withdrawals	(721)	(131)	(82)
Benefit payments	(68)	(59)	(23)
Investment performance	287	(319)	486
Net transfers from (to) general account and other	31	53	31
Balance, end of year	3,992	4,515	5,002
Cash surrender value	$ 3,994	$ 4,518	$ 4,993