MRBs - Summary of Balances of Changes in Net MRB (Assets) Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	$ (3,635)
Balance as of end-of-period	(3,176)
Variable Annuities
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(3,715)	$ (3,804)
Balance as of beginning-of-period, before the effect of changes in non-performance risk	(4,081)	(3,651)
Issuances	0	5
Attributed fees collected	375	373
Benefit payments	(7)	(6)
Effect of changes in interest rates	8	396
Effect of changes in equity markets	340	456
Effect of changes in equity index volatility	82	31
In-force updates and other changes in MRBs	199	59
Balance as of end-of-year, before the effect of changes in non-performance risk	(3,084)	(2,337)
Effect of cumulative changes in non-performance risk	(169)	(539)
Balance as of end-of-period	(3,253)	(2,876)
Less: Ceded MRB assets (liabilities)	(327)	(312)
Balance as of end-of-period, net of reinsurance	$ (2,926)	$ (2,564)
Weighted-average age of policyholders (years)	73 years	73 years
Net amount at risk	$ 2,652	$ 2,518
Variable Annuities | Cumulative Effect, Period of Adoption, Adjustment
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	366	(153)
Fixed Annuities
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	124	32
Balance as of beginning-of-period, before the effect of changes in non-performance risk	159	65
Issuances	0	0
Attributed fees collected	8	8
Benefit payments	0	0
Effect of changes in interest rates	(6)	39
Effect of changes in equity markets	8	2
Effect of changes in equity index volatility	0	0
In-force updates and other changes in MRBs	8	(2)
Balance as of end-of-year, before the effect of changes in non-performance risk	177	112
Effect of cumulative changes in non-performance risk	(58)	(48)
Balance as of end-of-period	119	64
Less: Ceded MRB assets (liabilities)	0	0
Balance as of end-of-period, net of reinsurance	$ 119	$ 64
Weighted-average age of policyholders (years)	71 years	70 years
Net amount at risk	$ 425	$ 255
Fixed Annuities | Cumulative Effect, Period of Adoption, Adjustment
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(35)	(33)
Retirement Plan Services
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(44)	(42)
Balance as of beginning-of-period, before the effect of changes in non-performance risk	(45)	(42)
Issuances	0	0
Attributed fees collected	2	1
Benefit payments	0	0
Effect of changes in interest rates	1	1
Effect of changes in equity markets	1	2
Effect of changes in equity index volatility	0	0
In-force updates and other changes in MRBs	0	1
Balance as of end-of-year, before the effect of changes in non-performance risk	(41)	(37)
Effect of cumulative changes in non-performance risk	(1)	(2)
Balance as of end-of-period	(42)	(39)
Less: Ceded MRB assets (liabilities)	0	0
Balance as of end-of-period, net of reinsurance	$ (42)	$ (39)
Weighted-average age of policyholders (years)	64 years	63 years
Net amount at risk	$ 3	$ 4
Retirement Plan Services | Cumulative Effect, Period of Adoption, Adjustment
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	$ 1	$ 0