Derivative and Hedging Activities Derivative Instruments Not Designated as Hedging Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Fair Value	$ 38,990	$ 33,023
Trading Assets [Member] \| Interest Rate Related Instruments Customer and Mirror [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	1,655,749	1,636,480
Fair Value	38,990	33,023
Receive Rate	1.50%	1.60%
Pay Rate	1.50%	1.60%
Maturity	41 months	42 months
Trading Assets [Member] \| Foreign Currency Exchange Forward [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	88,834	60,742
Fair Value	3,346	2,140
Trading Liabilities [Member] \| Interest Rate Related Instruments Customer and Mirror [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	1,655,749	1,636,480
Fair Value	(41,633)	(35,372)
Receive Rate	1.50%	1.60%
Pay Rate	1.50%	1.60%
Maturity	41 months	42 months
Trading Liabilities [Member] \| Foreign Currency Exchange Forward [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	79,934	56,573
Fair Value	(3,097)	(1,957)
Other Assets [Member] \| Interest Rate Lock Commitments (mortgage) [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	207,110	126,379
Fair Value	3,685	1,947
Other Assets [Member] \| Purchased deposit option [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	109,510	110,347
Fair Value	6,111	6,054
Other Liabilities [Member] \| Forward Commitments (mortgage) [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	309,275	234,500
Fair Value	(1,795)	(2,435)
Other Liabilities [Member] \| Written deposit option [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	109,510	110,347
Fair Value	$ (6,111)	$ (6,054)

Derivative Average Pay Interest Rate.

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- Definition

Derivative average receive interest rate.

+ References

No definition available.

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- Definition

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

+ References

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

+ Details

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- Definition

Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Net fair value of all derivative instruments not designated as a hedging instrument.

+ 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=28364263&loc=d3e13433-108611

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13495-108611

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