Loans and Leases (Recorded Investment in Each Class of Total Loans and Leases by Credit Quality Indicator) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 15,578		$ 12,307
Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	15,412		11,896
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	166		411
Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	12,015		9,205
Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,995		1,133
Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	291		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	137		377
Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	29		34
Investment grade
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	14,429		11,538	[1]
Investment grade | Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	11,574		8,937	[1]
Investment grade | Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,456		1,041	[1]
Investment grade | Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	291		394	[1]
Investment grade | Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,079		1,137	[1]
Investment grade | Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0		0	[1]
Investment grade | Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	29		29	[1]
Speculative
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,129		769	[2]
Speculative | Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	441		268	[2]
Speculative | Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	519		92	[2]
Speculative | Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0		0	[2]
Speculative | Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	32		27	[2]
Speculative | Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	137		377	[2]
Speculative | Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0		5	[2]
Special mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	20	[3]
Special mention | Investment Funds | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	[3]
Special mention | Commercial and Financial | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	20	[3]
Special mention | Purchased Receivables | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	[3]
Special mention | Lease Financing | Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	[3]
Special mention | Property Development | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	[3]
Special mention | Other | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 0	[3]

[1] Investment grade loans and leases consist of counterparties with strong credit quality and low expected credit risk and probability of default. Ratings apply to counterparties with a strong capacity to support the timely repayment of any financial commitment.

[2] Speculative loans and leases consist of counterparties that face ongoing uncertainties or exposure to business, financial, or economic downturns. However, these counterparties may have financial flexibility or access to financial alternatives, which allow for financial commitments to be met.

[3] Special mention loans and leases consist of counterparties with potential weaknesses that, if uncorrected, may result in deterioration of repayment prospects.