Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018		Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Service charges on deposit accounts	$ 146	[1]	$ 148	[2]
Fees and Commissions, Other	87	[1]	95	[2]
Fees and Commissions, Credit and Debit Cards	81	[1]	82	[2]
Investment Banking Revenue	131	[1]	167	[2]
Trading Gain (Loss)	42	[1]	51	[2]
Fees and Commissions, Fiduciary and Trust Activities	75	[1]	75	[2]
Investment Advisory, Management and Administrative Fees	72	[1]	68	[2]
Bank Servicing Fees	54	[1]	58	[2]
Fees and Commissions, Mortgage Banking	36	[1]	53	[2]
commercial real estate related income	23	[1]	20	[2]
Gain (Loss) on Sale of Securities, Net	1	[1]	0	[2]
Noninterest Income, Other Operating Income	48	[1]	30	[2]
Noninterest Income	796	[1]	847	[2],[3],[4]
Contract with Customer, Performance Obligation Satisfied in Previous Period	13
Excluded from Scope of ASC 606 - Consumer [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	105		127
Excluded from Scope of ASC 606 - Wholesale [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	215		229
Excluded from Scope of ASC 606 - Corporate Other [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	18		18
In Scope of ASC 606 - Consumer [Member]
Disaggregation of Revenue [Line Items]
Service charges on deposit accounts	104	[1],[5]	103	[2],[6]
Fees and Commissions, Other	28	[1],[5]	31	[2],[6]
Fees and Commissions, Credit and Debit Cards	54	[1],[5]	54	[2],[6]
Investment Banking Revenue	0	[1],[5]	0	[2],[6]
Trading Gain (Loss)	0	[1],[5]	0	[2],[6]
Fees and Commissions, Fiduciary and Trust Activities	75	[1],[5]	75	[2],[6]
Investment Advisory, Management and Administrative Fees	71	[1],[5]	67	[2],[6]
Bank Servicing Fees	0	[1],[5]	0	[2],[6]
Fees and Commissions, Mortgage Banking	0	[1],[5]	0	[2],[6]
commercial real estate related income	0	[1],[5]	0	[2],[6]
Gain (Loss) on Sale of Securities, Net	0	[1],[5]	0	[2],[6]
Noninterest Income, Other Operating Income	6	[1],[5]	7	[2],[6]
Noninterest Income	338	[1],[5]	337	[2],[6]
In Scope of ASC 606 - Wholesale [Member]
Disaggregation of Revenue [Line Items]
Service charges on deposit accounts	42	[1],[5]	45	[2],[6]
Fees and Commissions, Other	3	[1],[5]	3	[2],[6]
Fees and Commissions, Credit and Debit Cards	26	[1],[5]	27	[2],[6]
Investment Banking Revenue	84	[1],[5]	96	[2],[6]
Trading Gain (Loss)	0	[1],[5]	0	[2],[6]
Fees and Commissions, Fiduciary and Trust Activities	0	[1],[5]	0	[2],[6]
Investment Advisory, Management and Administrative Fees	1	[1],[5]	1	[2],[6]
Bank Servicing Fees	0	[1],[5]	0	[2],[6]
Fees and Commissions, Mortgage Banking	0	[1],[5]	0	[2],[6]
commercial real estate related income	0	[1],[5]	0	[2],[6]
Gain (Loss) on Sale of Securities, Net	0	[1],[5]	0	[2],[6]
Noninterest Income, Other Operating Income	0	[1],[5]	0	[2],[6]
Noninterest Income	156	[1],[5]	172	[2],[6]
Excluded from Scope of ASC 606 [Member]
Disaggregation of Revenue [Line Items]
Service charges on deposit accounts	0	[1],[5],[7]	0	[2],[6],[8]
Fees and Commissions, Other	56	[1],[5],[7]	61	[2],[6],[8]
Fees and Commissions, Credit and Debit Cards	1	[1],[5],[7]	1	[2],[6],[8]
Investment Banking Revenue	47	[1],[5],[7]	71	[2],[6],[8]
Trading Gain (Loss)	42	[1],[5],[7]	51	[2],[6],[8]
Fees and Commissions, Fiduciary and Trust Activities	0	[1],[5],[7]	0	[2],[6],[8]
Investment Advisory, Management and Administrative Fees	0	[1],[5],[7]	0	[2],[6],[8]
Bank Servicing Fees	54	[1],[5],[7]	58	[2],[6],[8]
Fees and Commissions, Mortgage Banking	36	[1],[5],[7]	53	[2],[6],[8]
commercial real estate related income	23	[1],[5],[7]	20	[2],[6],[8]
Gain (Loss) on Sale of Securities, Net	1	[1],[5],[7]	0	[2],[6],[8]
Noninterest Income, Other Operating Income	42	[1],[5],[7]	23	[2],[6],[8]
Noninterest Income	$ 302	[1],[5],[7]	$ 338	[2],[6],[8]

[1] Amounts are presented in accordance with ASC Topic 606, Revenue from Contracts with Customers.

[2] Amounts for periods prior to January 1, 2018 are presented in accordance with ASC Topic 605, Revenue Recognition, and have not been restated to conform with ASC Topic 606, Revenue from Contracts with Customers.

[3] Beginning in the second quarter of 2017, the Company realigned its business segment structure from three segments to two segments. Specifically, the Company retained the previous composition of the Wholesale Banking segment and changed the basis of presentation of the Consumer Banking and Private Wealth Management segment and Mortgage Banking segment such that those segments were combined into a single Consumer segment. Accordingly, business segment information presented for the three months ended March 31, 2017 has been revised to conform to the new business segment structure and updated internal funds transfer pricing methodology for consistent presentation.

[4] During the fourth quarter of 2017, the Company sold PAC, the results of which were previously reported within the Wholesale business segment. For all periods prior to January 1, 2018, PAC's financial results, including the gain on sale, have been transferred to Corporate Other for enhanced comparability of the Wholesale business segment excluding PAC.

[5] Consumer and Wholesale totals exclude $105 million and $215 million of out of scope noninterest income, respectively, that is included in the business segment results presented on a management accounting basis in Note 18, "Business Segment Reporting." Total out of scope noninterest income includes these amounts as well as ($18) million of Corporate Other noninterest income that is out of scope of ASC Topic 606.

[6] Consumer and Wholesale totals exclude $127 million and $229 million of out of scope noninterest income, respectively, that is included in the business segment results presented on a management accounting basis in Note 18, "Business Segment Reporting." Total out of scope noninterest income includes these amounts as well as ($18) million of Corporate Other noninterest income that is out of scope of ASC Topic 606.

[7] The Company presents out of scope noninterest income for the purpose of reconciling noninterest income amounts within the scope of ASC Topic 606 to noninterest income amounts presented on the Company's Consolidated Statements of Income.

[8] The Company presents out of scope noninterest income for the purpose of reconciling noninterest income amounts within the scope of ASC Topic 606 to noninterest income amounts presented on the Company's Consolidated Statements of Income.