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	$ 8,604	$ 25,934
Balance as of end-of-year	10,507	8,604	$ 25,934
Unrealized Gain (Loss) on Fixed Maturity AFS Securities and Certain Other Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(8,526)	9,153	8,993
Income tax benefit (expense)	(650)	4,815	797
Reclassification adjustment for gains (losses) included in net income (loss)	(3,425)	(13)	624
Income tax benefit (expense)	719	3	(131)
Balance as of end-of-year	(3,532)	(8,526)	9,153
Unrealized holding gains (losses) arising during the year
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	2,122	(24,475)	(4,478)
Change in foreign currency exchange rate adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	178	(321)	(143)
Change in future contract benefits and policyholder account balances, net of reinsurance
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	638	2,292	893
Unrealized Gain (Loss) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	301	258	42
Income tax benefit (expense)	2	(34)	(63)
Reclassification adjustment for gains (losses) included in net income (loss)	60	103	49
Income tax benefit (expense)	(13)	(22)	(10)
Balance as of end-of-year	249	301	258
Unrealized holding gains (losses) arising during the year
Accumulated Other Comprehensive Income (Loss) [Line Items]
Changes arising during the year	162	(154)	141
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	1,739	1,951	0
Adjustment arising during the year	(854)	(267)	(1,174)
Income tax benefit (expense)	184	55	251
Balance as of end-of-year	1,069	1,739	1,951
Policyholder Liability Discount Rate Remeasurement Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	790	(1,101)	0
Adjustment arising during the year	(187)	2,406	711
Income tax benefit (expense)	42	(515)	(151)
Balance as of end-of-year	645	790	(1,101)
Funded Status of Employee Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year	(17)	(11)	(14)
Adjustment arising during the year	1	(6)	4
Income tax benefit (expense)	0	0	(1)
Balance as of end-of-year	$ (16)	$ (17)	(11)
Cumulative effect from adoption of new accounting standards
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			4,822
Cumulative effect from adoption of new accounting standards | Unrealized Gain (Loss) on Fixed Maturity AFS Securities and Certain Other Investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			3,584
Cumulative effect from adoption of new accounting standards | Unrealized Gain (Loss) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			25
Cumulative effect from adoption of new accounting standards | 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 from adoption of new accounting standards | Policyholder Liability Discount Rate Remeasurement Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of beginning-of-year			$ (1,661)