Loans and Leases - Net Loans (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 19,067	$ 18,199
Allowance for loan losses	(48)	(38)
Loans and leases, net of allowance for loan losses	19,019	18,161
Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	19,016	18,171
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	51	28
U.S. | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment funds	11,875	11,388
Commercial and financial	3,328	3,061
Purchased receivables	99	124
Lease financing	337	335
U.S. | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial real estate	51	28
Non- U.S. | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment funds	2,144	2,333
Commercial and financial	653	256
Purchased receivables	0	6
Lease financing	$ 580	$ 668