Loans and Leases - Net Loans (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 18,590	$ 18,199
Allowance for loan losses	(43)	(38)
Loans and leases, net of allowance for loan losses	18,547	18,161
Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	18,555	18,171
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	35	28
U.S. | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment funds	11,126	11,388
Commercial and financial	3,358	3,061
Purchased receivables	107	124
Lease financing	335	335
U.S. | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial real estate	35	28
Non-U.S. | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment funds	2,686	2,333
Commercial and financial	334	256
Purchased receivables	2	6
Lease financing	$ 607	$ 668