Deposits and Borrowings Deposits and Borrowings - Schedule of Maturity Profile of Borrowing and Debt (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Time Deposits, Fiscal Year Maturity:
2018	$ 9,025
2019	7,147
2020	5,395
2021	3,851
2022	4,104
Thereafter	158
Total	29,680
Debt Fiscal Year Maturity:
Secured Debt	20,010	$ 18,826
Total, Fiscal Year Maturity:
2018	17,187
2019	19,708
2020	23,647
2021	8,997
2022	9,176
Thereafter	11,246
Total	89,961
Senior and Subordinated Notes
Debt Fiscal Year Maturity:
Total	30,755
other borrowings [Member]
Time Deposits, Fiscal Year Maturity:
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	230
Senior and Subordinated Notes
Time Deposits, Fiscal Year Maturity:
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	4,690
Debt Fiscal Year Maturity:
2019	5,667
2020	4,360
2021	3,445
2022	2,518
Thereafter	10,075
Long-term Debt	30,755	23,431
Securitized debt obligations
Time Deposits, Fiscal Year Maturity:
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	2,666
Debt Fiscal Year Maturity:
2019	6,828
2020	5,289
2021	1,698
2022	2,552
Thereafter	977
Long-term Debt	20,010	18,826
FHLB Advance Capital Lease Obligation and GPMH
Debt Fiscal Year Maturity:
2019	66
2020	8,603
2021	3
2022	2
Thereafter	36
Long-term Debt	8,940	$ 17,211
Federal funds purchased and securities loaned or sold under agreements to repurchase
Debt Fiscal Year Maturity:
Short-term debt, maturities, next 12 months	$ 576