Other Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Components of Other Assets [Line Items]
Corporate/bank-owned life insurance	$ 20,567	$ 20,380
Accounts receivable	19,014	38,116
Customer relationship and other amortized intangibles	1,553	1,640
Residential real estate foreclosed assets	47	73
Other foreclosed assets	74	86
Operating lease assets (lessor)	6,611	7,391
Operating lease ROU assets (lessee)	3,990	4,306
Due from customers on acceptances	132	268
Other	12,224	11,768
Total other assets	66,769	87,337
Customer relationship and other amortized intangibles [Member]
Components of Other Assets [Line Items]
Customer relationship and other amortized intangibles	267	328
AFS And HTM debt securities [Member]
Components of Other Assets [Line Items]
Interest receivable	1,350	1,368
Loans [Member]
Components of Other Assets [Line Items]
Interest receivable	2,147	2,838
Trading and other [Member]
Components of Other Assets [Line Items]
Interest receivable	$ 346	$ 415