Derivatives (Derivatives Associated with Capital Markets Trading Activities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Customer Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 1,754,939,000	$ 1,786,532,000
Assets	76,614,000	76,980,000
Liabilities	3,681,000	11,214,000
Offsetting Upstream Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	1,754,939,000	1,786,532,000
Assets	3,681,000	11,214,000
Liabilities	76,614,000	76,980,000
Put Option [Member] \| LongMember
Derivative Instruments, Gain (Loss) [Line Items]
Notional	15,000,000	5,000,000
Assets	12,000	9,000
Liabilities	0	0
Forwards And Futures Purchased [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	884,439,000	1,278,331,000
Assets	1,383,000	2,489,000
Liabilities	459,000	824,000
Forwards And Futures Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional	1,175,667,000	1,445,656,000
Assets	962,000	531,000
Liabilities	$ 1,576,000	$ 3,519,000

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611

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Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

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