Future Policy Benefits - Income statement information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	$ 2,519	$ 2,291
Interest accretion	596	517
Universal Life
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	258	309
Interest accretion	39	29
Individual Retirement
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	39	75
Interest accretion	16	12
Group Retirement
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	5	6
Interest accretion	3	3
Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	618	575
Interest accretion	119	118
Life Insurance \| Universal Life
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	248	299
Interest accretion	38	28
Institutional Markets
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	1,805	1,581
Interest accretion	217	139
Corporate and Other
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	52	54
Interest accretion	241	245
Corporate and Other \| Universal Life
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	10	10
Interest accretion	$ 1	$ 1