Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Jan. 01, 2023	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Summary of Significant Accounting Policies [Line Items]
Earning pattern of reinsurance contract extension (in years)	24 months
Stockholders' equity	$ 42,235			$ 68,912	$ 67,199	$ 67,427
Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity	(22,092)			6,687	13,511	4,982
Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity	$ 33,032			$ 23,785	$ 15,504	23,084
Cumulative effect of change in accounting principle
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity						(487)
Cumulative effect of change in accounting principle | Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity						$ (487)
ASU 2018-12 | Cumulative effect of change in accounting principle | Minimum
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity			$ 800
ASU 2018-12 | Cumulative effect of change in accounting principle | Minimum | Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity			(400)
ASU 2018-12 | Cumulative effect of change in accounting principle | Minimum | Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity			1,200
ASU 2018-12 | Cumulative effect of change in accounting principle | Maximum
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity			1,300
ASU 2018-12 | Cumulative effect of change in accounting principle | Maximum | Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity			(900)
ASU 2018-12 | Cumulative effect of change in accounting principle | Maximum | Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity			$ 1,700
ASU 2018-12 | Cumulative effect of change in accounting principle | Forecast | Minimum
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity		$ (1,000)
ASU 2018-12 | Cumulative effect of change in accounting principle | Forecast | Minimum | Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity		(1,800)
ASU 2018-12 | Cumulative effect of change in accounting principle | Forecast | Minimum | Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity		800
ASU 2018-12 | Cumulative effect of change in accounting principle | Forecast | Maximum
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity		(1,500)
ASU 2018-12 | Cumulative effect of change in accounting principle | Forecast | Maximum | Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity		(2,300)
ASU 2018-12 | Cumulative effect of change in accounting principle | Forecast | Maximum | Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity		$ 1,300
Building | Maximum
Summary of Significant Accounting Policies [Line Items]
Useful life (in years)	40 years
Furniture and Fixtures | Maximum
Summary of Significant Accounting Policies [Line Items]
Useful life (in years)	10 years
Capitalized Software Costs | Maximum
Summary of Significant Accounting Policies [Line Items]
Useful life (in years)	10 years