Investments - Net Realized Capital Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	$ (30)	$ (26)	$ (99)	$ (22)
Embedded derivatives with fixed maturities
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	1	2	7	1
Other derivatives, net
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	(3)	0	(2)	1
Managed Custody Guarantees
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	2	6	3	6
Stabilizer
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	5	(6)	10	(7)
Derivatives
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	5	(106)	(65)	4
Mortgages [Member]
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	(2)	(4)	(5)	(1)
Other investments
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	2	0	1	0
Fixed Maturities, Available-for-sale, Including Securities Pledged
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	13	18	(5)	(7)
Fixed Maturities, at Fair Value Using the Fair Value Option
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	(48)	62	(39)	(23)
Equity securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Realized capital gains (losses)	$ (5)	$ 2	$ (4)	$ 4