Shares and Stockholders' Equity - Components and Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	$ 10,507	$ 8,604
Balance as of end-of-year	10,512	10,507	$ 8,604
Unrealized Gain (Loss) on Fixed Maturity AFS Securities and Certain
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(3,532)	(8,526)	9,153
Income tax benefit (expense)	64	(650)	4,815
Reclassification adjustment for gains (losses) included in net income (loss)	(173)	(3,425)	(13)
Income tax benefit (expense)	36	719	3
Balance as of end-of-year	(3,655)	(3,532)	(8,526)
Unrealized holding gains (losses) arising during the year
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	(1,294)	2,122	(24,475)
Change in foreign currency exchange rate adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	(219)	178	(321)
Change in future contract benefits and policyholder account balances, net of reinsurance
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	1,189	638	2,292
Unrealized Gain (Loss) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	249	301	258
Income tax benefit (expense)	(54)	2	(34)
Reclassification adjustment for gains (losses) included in net income (loss)	64	60	103
Income tax benefit (expense)	(13)	(13)	(22)
Balance as of end-of-year	402	249	301
Unrealized holding gains (losses) arising during the year
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	38	162	(154)
Change in foreign currency exchange rate adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	220	(169)	312
Market Risk Benefit Non-Performance Risk Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	1,069	1,739	1,951
Adjustment arising during the year	(1,175)	(854)	(267)
Income tax benefit (expense)	251	184	55
Balance as of end-of-year	145	1,069	1,739
Policyholder Liability Discount Rate Remeasurement Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	645	790	(1,101)
Adjustment arising during the year	189	(187)	2,406
Income tax benefit (expense)	(39)	42	(515)
Balance as of end-of-year	795	645	790
Funded Status of Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(16)	(17)	(11)
Adjustment arising during the year	(1)	1	(6)
Balance as of end-of-year	$ (17)	$ (16)	$ (17)