Basis of Presentation (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to allowance for credit losses	$ (21,946)		$ (19,726)	$ (18,185)		$ (16,386)
Increase to retained earnings	317,371		292,332	288,018
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to retained earnings	$ 327,044	$ 317,359	296,456	$ 288,776	$ 282,445	$ 272,268
Cumulative effect of change in accounting principles | Accounting Standards Update 2022-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to allowance for credit losses			587
Cumulative effect of change in accounting principles | Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to retained earnings			449
Cumulative effect of change in accounting principles | Retained earnings | Accounting Standards Update 2022-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to retained earnings			$ 446