MRBs - Summary of Balances of Changes in Net MRB (Assets) Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	$ (3,814)
Balance as of end-of-period	(3,504)
Variable Annuities
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(3,804)	$ (2,180)
Balance as of beginning-of-year, before the effect of changes in non-performance risk	(3,651)	(881)
Issuances	12	6
Attributed fees collected	1,105	1,143
Benefit payments	(20)	(29)
Effect of changes in interest rates	75	(101)
Effect of changes in equity markets	(1,667)	(2,347)
Effect of changes in equity index volatility	36	(65)
In-force updates and other changes in MRBs	367	69
Effect of changes in future expected policyholder behavior	37	7
Effect of changes in other future expected assumptions	10	(199)
Balance as of end-of-period, before the effect of changes in non-performance risk	(3,696)	(2,397)
Effect of cumulative changes in non-performance risk	114	(930)
Balance as of end-of-period	(3,582)	(3,327)
Less: Ceded MRB assets (liabilities)	(2,661)	(2,155)
Balance as of end-of-period, net of reinsurance	$ (921)	$ (1,172)
Weighted-average age of policyholders (years)	73 years	72 years
Net amount at risk	$ 1,442	$ 1,544
Variable Annuities | Cumulative effect from adoption of new accounting standards
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(153)	(1,299)
Fixed Annuities
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	32	32
Balance as of beginning-of-year, before the effect of changes in non-performance risk	65	90
Issuances	0	0
Attributed fees collected	23	24
Benefit payments	0	0
Effect of changes in interest rates	38	8
Effect of changes in equity markets	(6)	(16)
Effect of changes in equity index volatility	7	(4)
In-force updates and other changes in MRBs	19	3
Effect of changes in future expected policyholder behavior	15	11
Effect of changes in other future expected assumptions	0	18
Balance as of end-of-period, before the effect of changes in non-performance risk	161	134
Effect of cumulative changes in non-performance risk	(40)	(60)
Balance as of end-of-period	121	74
Less: Ceded MRB assets (liabilities)	0	0
Balance as of end-of-period, net of reinsurance	$ 121	$ 74
Weighted-average age of policyholders (years)	70 years	69 years
Net amount at risk	$ 288	$ 231
Fixed Annuities | Cumulative effect from adoption of new accounting standards
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(33)	(58)
Retirement Plan Services
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	(42)	(30)
Balance as of beginning-of-year, before the effect of changes in non-performance risk	(42)	(26)
Issuances	0	0
Attributed fees collected	5	4
Benefit payments	0	0
Effect of changes in interest rates	(3)	(6)
Effect of changes in equity markets	(6)	(8)
Effect of changes in equity index volatility	0	0
In-force updates and other changes in MRBs	3	6
Effect of changes in future expected policyholder behavior	(1)	0
Effect of changes in other future expected assumptions	1	(6)
Balance as of end-of-period, before the effect of changes in non-performance risk	(43)	(36)
Effect of cumulative changes in non-performance risk	0	(4)
Balance as of end-of-period	(43)	(40)
Less: Ceded MRB assets (liabilities)	(11)	(12)
Balance as of end-of-period, net of reinsurance	$ (32)	$ (28)
Weighted-average age of policyholders (years)	63 years	63 years
Net amount at risk	$ 2	$ 3
Retirement Plan Services | Cumulative effect from adoption of new accounting standards
Market Risk Benefit [Roll Forward]
Balance as of beginning-of-year	$ 0	$ (4)