Recent Accounting Pronouncements - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022		Sep. 30, 2022	[2]	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Recent accounting pronouncements
Reduction in equity	$ (3,825)	$ (4,080)	$ (3,803)	[1]	$ (3,618)		$ (4,070)	$ (4,837)
Adjustment
Recent accounting pronouncements
Reduction in equity			(190)					1,104	$ 1,900
Retained Earnings
Recent accounting pronouncements
Reduction in equity	(21,670)	(20,941)	(19,918)		(19,406)		(18,486)	(17,322)
Retained Earnings | Adjustment
Recent accounting pronouncements
Reduction in equity									900
Accumulated Other Comprehensive Income (Loss)
Recent accounting pronouncements
Reduction in equity	$ 2,840	$ 2,349	$ 2,546		$ 2,665		$ 1,748	$ 642
Accumulated Other Comprehensive Income (Loss) | Adjustment
Recent accounting pronouncements
Reduction in equity									$ 1,000

[1] Certain prior period amounts have been restated. See Note 3 for more information.

[2] Certain prior period amounts have been restated. See Note 3 for more information.