Shares and Stockholders' Equity - Components and Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	$ 5,102	$ 19,915
Balance as of end-of-year	6,893	5,102	$ 19,915
Unrealized Gain (Loss) on Fixed Maturity AFS Securities and Certain
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(8,916)	9,616	9,611
Income tax benefit (expense)	(849)	5,039	838
Reclassification adjustment for gains (losses) included in net income (loss)	(860)	(15)	626
Income tax benefit (expense)	181	3	(131)
Balance as of end-of-year	(5,188)	(8,916)	9,616
Unrealized holding gains (losses) arising during the year
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	2,413	(25,552)	(4,673)
Change in foreign currency exchange rate adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	179	(322)	(142)
Change in future contract benefits and policyholder account balances, net of reinsurance
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	1,306	2,291	893
Unrealized Gain (Loss) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	388	(85)	(402)
Income tax benefit (expense)	(15)	(144)	(85)
Reclassification adjustment for gains (losses) included in net income (loss)	91	92	26
Income tax benefit (expense)	(19)	(19)	(5)
Balance as of end-of-year	375	388	(85)
Unrealized holding gains (losses) arising during the year
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	243	378	246
Change in foreign currency exchange rate adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	(169)	312	152
Market Risk Benefit Non-Performance Risk Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	1,741	1,951	0
Adjustment arising during the year	(854)	(266)	(1,174)
Income tax benefit (expense)	183	56	251
Balance as of end-of-year	1,070	1,741	1,951
Policyholder Liability Discount Rate Remeasurement Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	747	(1,265)	0
Adjustment arising during the year	(206)	2,559	751
Income tax benefit (expense)	46	(547)	(160)
Balance as of end-of-year	587	747	(1,265)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(34)	(14)	(12)
Foreign currency translation adjustment arising during the year	8	(20)	(2)
Balance as of end-of-year	(26)	(34)	(14)
Funded Status of Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(278)	(219)	(266)
Adjustment arising during the year	(13)	(74)	56
Income tax benefit (expense)	(3)	15	(9)
Balance as of end-of-year	$ (294)	$ (278)	(219)
Cumulative Effect to Retained Earnings | Unrealized Gain (Loss) on Fixed Maturity AFS Securities and Certain
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			3,584
Cumulative Effect to Retained Earnings | Unrealized Gain (Loss) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			25
Cumulative Effect to Retained Earnings | Market Risk Benefit Non-Performance Risk Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			2,874
Cumulative Effect to Retained Earnings | Policyholder Liability Discount Rate Remeasurement Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			$ (1,856)