Parent Company Financial Statements - Statement of Condition (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Interest-bearing deposits with banks	$ 116,960	$ 68,965
Trading account assets	815	914
Investment securities available-for-sale	59,048	53,815
Other assets	36,510	34,011
Total assets	314,706	245,610
Liabilities:
Total liabilities	288,506	221,179
Shareholders’ equity	26,200	24,431	$ 24,737	$ 22,270
Total liabilities and shareholders' equity	314,706	245,610
Parent Company
Assets:
Interest-bearing deposits with banks	492	428
Trading account assets	412	393
Investment securities available-for-sale	100	250
Consolidated banking subsidiary	26,204	25,451
Consolidated non-banking subsidiaries	8,807	7,240
Unconsolidated entities	124	117
Consolidated banking subsidiary	81	0
Consolidated non-banking subsidiaries and unconsolidated entities	3,885	3,361
Other assets	277	270
Total assets	40,382	37,510
Liabilities:
Accrued expenses and other liabilities	557	696
Long-term debt	13,625	12,383
Total liabilities	14,182	13,079
Shareholders’ equity	26,200	24,431
Total liabilities and shareholders' equity	$ 40,382	$ 37,510