Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	[1]	Jan. 01, 2021
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity	$ (43,213)	$ (46,491)	$ (43,454)	$ (42,113)	$ (47,224)	$ (69,034)		$ (65,935)
Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity	22,529	18,982	22,616	24,120	18,647	(5,071)
Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity	$ (37,689)	$ (35,916)	$ (34,893)	$ (34,588)	$ (32,091)	$ (25,695)
Cumulative effect of change in accounting principle | Minimum | ASU 2018-12 | Accumulated Other Comprehensive Income (Loss)
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity								(2,200)
Cumulative effect of change in accounting principle | Minimum | ASU 2018-12 | Retained Earnings
Summary of Significant Accounting Policies [Line Items]
Stockholders' equity								$ (933)

[1] Updated to reflect the adoption of long-duration targets improvements, see Note 2.