Separate Accounts (Summary of Balances and changes in Separate Account Liabilities) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Separate Account, Liability [Line Items]
Balance as of beginning-of-year	$ 143,536
Balance as of end-of-period	145,810	$ 143,536
UL and Other [Member]
Separate Account, Liability [Line Items]
Balance as of beginning-of-year	20,920	24,785
Gross Deposit	1,178	1,900
Withdrawal	(227)	(454)
Policyholder assessments	(714)	(938)
Change in market performance	1,573	(4,371)
Net transfers from (to) general account	(88)	(2)
Balance as of end-of-period	22,642	20,920
Cash surrender value	20,324	18,666
Variable Annuities [Member]
Separate Account, Liability [Line Items]
Balance as of beginning-of-year	105,573	136,665
Gross Deposit	2,137	3,371
Withdrawal	(7,402)	(9,238)
Policyholder assessments	(1,883)	(2,603)
Change in market performance	6,320	(23,194)
Net transfers from (to) general account	447	572
Balance as of end-of-period	105,192	105,573
Cash surrender value	103,729	103,987
Retirement Plan Services Segment [Member]
Separate Account, Liability [Line Items]
Balance as of beginning-of-year	16,996	21,068
Gross Deposit	1,576	2,378
Withdrawal	(1,795)	(2,378)
Policyholder assessments	(121)	(164)
Change in market performance	1,316	(3,710)
Net transfers from (to) general account	(44)	(198)
Balance as of end-of-period	17,928	16,996
Cash surrender value	$ 17,914	$ 16,982