Parent Company Financial Statements - Statement of Condition (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets:
Interest-bearing deposits with banks	$ 70,935	$ 75,338
Trading account assets	1,024	849
Investment securities available-for-sale	61,998	70,070
Other assets	38,328	33,903
Total assets	242,698	245,155
Liabilities:
Total liabilities	221,479	224,020
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shareholders’ equity	21,219	21,103	$ 21,328	$ 20,248
Total liabilities and shareholders' equity	242,698	245,155
Parent Company
Assets:
Interest-bearing deposits with banks	3,635	5,735
Trading account assets	325	308
Investment securities available-for-sale	39	35
Consolidated banking subsidiary	22,147	20,584
Consolidated non-banking subsidiaries	2,687	2,816
Unconsolidated entities	297	315
Consolidated banking subsidiary	2,743	1,558
Consolidated non-banking subsidiaries and unconsolidated entities	126	275
Other assets	461	478
Total assets	32,460	32,104
Liabilities:
Accrued expenses and other liabilities	514	643
Long-term debt	10,727	10,326
Total liabilities	11,241	10,969
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shareholders’ equity	21,219	21,135
Total liabilities and shareholders' equity	$ 32,460	$ 32,104