Parent Company Financial Statements - Statement of Condition (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets:
Interest-bearing deposits with banks	$ 73,040	$ 67,227
Trading account assets	860	1,093
Investment securities available-for-sale	45,148	57,121
Other assets	34,434	31,018
Total assets	244,626	238,425
Liabilities:
Total liabilities	219,836	216,108
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shareholders’ equity	24,790	22,317	$ 21,219	$ 21,103
Total liabilities and shareholders' equity	244,626	238,425
Parent Company
Assets:
Interest-bearing deposits with banks	486	532
Trading account assets	357	361
Investment securities available-for-sale	224	43
Consolidated banking subsidiary	26,019	23,080
Consolidated non-banking subsidiaries	6,726	6,762
Unconsolidated entities	106	63
Consolidated banking subsidiary	64	273
Consolidated non-banking subsidiaries and unconsolidated entities	2,337	2,843
Other assets	96	263
Total assets	36,415	34,220
Liabilities:
Accrued expenses and other liabilities	685	917
Long-term debt	10,940	10,986
Total liabilities	11,625	11,903
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shareholders’ equity	24,790	22,317
Total liabilities and shareholders' equity	$ 36,415	$ 34,220