Loans and Leases (Narrative) (Details) (USD $)	12 Months Ended
Dec. 31, 2013 loan	Mar. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, allowance for losses	$ 28,000,000	$ 30,000,000
Aggregate short-duration advances	2,450,000,000	4,830,000,000
Loans modified in troubled debt restructurings	0
Institutional
Financing Receivable, Recorded Investment [Line Items]
Amount of loan losses related to institutional loans collectively evaluated for impairment	28,000,000	30,000,000
Institutional \| Senior Secured Bank Loans
Financing Receivable, Recorded Investment [Line Items]
Commercial and financial	724,000,000	1,150,000,000
Commercial and Financial \| Senior Secured Bank Loans
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, allowance for losses		8,000,000
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Amount of loan losses related to institutional loans collectively evaluated for impairment		28,000,000
Loan modification, recorded investment	130,000,000	130,000,000
Impairment loss recognized	$ 0

Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.5-02.20)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 45

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Amount of direct write-downs of financing receivables charged against the allowance.

+ References

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-Name Accounting Standards Codification

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The balance of financing receivables that were collectively evaluated for impairment.

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Number of financing receivables that have been modified by troubled debt restructurings.

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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-Subparagraph (SX 210.9-03.7(d))

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-Name Regulation S-X (SX)

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Amount before allowance of loans issued to financial institutions, including, but not limited to, real estate investment trusts, mortgage companies, and banks. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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