Loans and Leases - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($) loan loan_segment	Dec. 31, 2014 USD ($) loan	Dec. 31, 2013 USD ($)
Financing Receivable, Recorded Investment [Line Items]
Number of Loan Segments \| loan_segment	2
Aggregate short-duration advances	$ 2,620	$ 3,540
Loans and leases, allowance for losses	$ 46	$ 38
Loans modified in troubled debt restructurings \| loan	0	0
Number of consecutive days past due for non-accrual status	60 days
Provision for loan losses	$ 12	$ 10	$ 6
Charge-offs	(4)	0	$ 0
Commercial and Financial
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, allowance for losses	11
Commercial and Financial \| Senior Secured Bank Loans
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, allowance for losses	$ 35	$ 26
Institutional
Financing Receivable, Recorded Investment [Line Items]
Loans more than 90 days past due \| loan	0	0
Institutional \| Senior Secured Bank Loans
Financing Receivable, Recorded Investment [Line Items]
Commercial and financial	$ 3,140	$ 2,070
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Loans more than 90 days past due \| loan	0	0

Financing Receivable, Consecutive Days Past Due for Non-accrual Status

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Financing Receivable Recorded Investment Equal To Greater Than 90 Day

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- Definition

Number of Loan Segments

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No definition available.

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

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.

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-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 6
-Section L
-Subsection 1

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- Definition

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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Amount of expense related to estimated loss from loan and lease transactions.

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