Insurance Liabilities - Unearned revenue liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Policyholder Funds Rollforward [Roll Forward]
Balance, beginning of year	$ 1,834	$ 1,811	$ 1,795
Revenue deferred	153	143	140
Amortization	(122)	(120)	(123)
Other, including foreign exchange			(1)
Balance, end of year	1,865	1,834	1,811
Life Insurance
Other Policyholder Funds Rollforward [Roll Forward]
Balance, beginning of year	1,727	1,693	1,661
Revenue deferred	153	143	140
Amortization	(110)	(109)	(108)
Other, including foreign exchange			0
Balance, end of year	1,770	1,727	1,693
Institutional Markets
Other Policyholder Funds Rollforward [Roll Forward]
Balance, beginning of year	2	2	2
Revenue deferred	0	0	0
Amortization	(1)	0	0
Other, including foreign exchange			0
Balance, end of year	1	2	2
Corporate and Other [Member]
Other Policyholder Funds Rollforward [Roll Forward]
Balance, beginning of year	105	116	132
Revenue deferred	0	0	0
Amortization	(11)	(11)	(15)
Other, including foreign exchange			(1)
Balance, end of year	94	105	116
Other reconciling items	$ 1,500	$ 1,600	$ 1,700