Separate Account Assets and Liabilities - Separate account liabilities (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Separate Account, Liability [Roll Forward]
Balance, beginning of year	$ 84,853	$ 109,111
Premiums and deposits	846	1,238
Policy charges	(490)	(486)
Surrenders and withdrawals	(1,923)	(1,656)
Benefit payments	(400)	(406)
Investment performance	4,469	(6,870)
Net transfers from (to) general account	1	(82)
Other charges	1	1
Balance, end of period	87,357	100,850
Cash surrender value	86,076	99,444
Individual Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	45,178	57,927
Premiums and deposits	451	758
Policy charges	(344)	(321)
Surrenders and withdrawals	(844)	(934)
Benefit payments	(215)	(255)
Investment performance	2,131	(3,718)
Net transfers from (to) general account	73	44
Other charges	0	(1)
Balance, end of period	46,430	53,500
Cash surrender value	45,388	52,334
Group Retirement
Separate Account, Liability [Roll Forward]
Balance, beginning of year	34,361	45,138
Premiums and deposits	360	440
Policy charges	(110)	(127)
Surrenders and withdrawals	(669)	(696)
Benefit payments	(130)	(144)
Investment performance	2,186	(2,992)
Net transfers from (to) general account	(77)	(134)
Other charges	(1)	1
Balance, end of period	35,920	41,486
Cash surrender value	35,726	41,263
Life Insurance
Separate Account, Liability [Roll Forward]
Balance, beginning of year	799	1,044
Premiums and deposits	9	10
Policy charges	(12)	(13)
Surrenders and withdrawals	(6)	(6)
Benefit payments	(1)	(2)
Investment performance	53	(73)
Net transfers from (to) general account	(1)	0
Other charges	0	0
Balance, end of period	841	960
Cash surrender value	794	949
Institutional Markets
Separate Account, Liability [Roll Forward]
Balance, beginning of year	4,515	5,002
Premiums and deposits	26	30
Policy charges	(24)	(25)
Surrenders and withdrawals	(404)	(20)
Benefit payments	(54)	(5)
Investment performance	99	(87)
Net transfers from (to) general account	6	8
Other charges	2	1
Balance, end of period	4,166	4,904
Cash surrender value	$ 4,168	$ 4,898

Transfer To (From) Policyholder Account Balance (To) From General Account

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- Definition

Amount of cash outflow to separate account policyholder from benefit payment.

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Amount of separate account liability payable to policyholder upon surrender of contract before maturity.

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Amount of increase (decrease) in separate account liability from performance of investment.

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Amount increase (decrease) in separate account liability from change, classified as other.

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Amount of decrease in separate account liability from policy charge.

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- Definition

Amount of cash inflow to separate account liability from premium and deposit from cash received.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of decrease in separate account liability from contract redemption and withdrawal of funds.

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- Definition

Amount of liability for variable contract in which all or portion of contract holder's funds is allocated to specific separate account and supported by assets held in separate account.

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