Goodwill and Other Intangible Assets Goodwill and Other Intangible Assets-Accumulated Amortization of Intangible Assets Schedule (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 96,561	$ 96,561	$ 101,771
Finite-Lived Intangible Assets, Accumulated Amortization	(28,139)	(25,541)	(21,952)
Finite-Lived Intangible Assets, Net	68,422us-gaap_FiniteLivedIntangibleAssetsNet	71,020us-gaap_FiniteLivedIntangibleAssetsNet	79,819us-gaap_FiniteLivedIntangibleAssetsNet
Core Deposits
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	82,323	82,323	87,533
Finite-Lived Intangible Assets, Accumulated Amortization	(22,073)	(19,996)	(18,352)
Finite-Lived Intangible Assets, Net	60,250	62,327	69,181
Lease Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	238	238	238
Finite-Lived Intangible Assets, Accumulated Amortization	(185)	(176)	(149)
Finite-Lived Intangible Assets, Net	53	62	89
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	14,000	14,000	14,000
Finite-Lived Intangible Assets, Accumulated Amortization	(5,881)	(5,369)	(3,451)
Finite-Lived Intangible Assets, Net	$ 8,119	$ 8,631	$ 10,549

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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