Loans and Leases (Recorded Investment in Each Class of Total Loans and Leases by Credit Quality Indicator) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 16,431	$ 12,307
Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	16,266	11,896
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	165	411
Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	13,309	9,205
Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,523	1,133
Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	323	394
Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,111	1,164
Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	131	377
Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	34	34
Investment grade
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	15,815	11,538
Investment grade | Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	12,942	8,937
Investment grade | Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,445	1,041
Investment grade | Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	323	394
Investment grade | Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,076	1,137
Investment grade | Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	0
Investment grade | Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	29	29
Speculative
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	595	769
Speculative | Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	367	268
Speculative | Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	57	92
Speculative | Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	0
Speculative | Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	35	27
Speculative | Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	131	377
Speculative | Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	5	5
Special mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	21
Special mention | Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0
Special mention | Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	21
Special mention | Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0
Special mention | Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0
Special mention | Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0
Special mention | Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 0