Loans and the Allowance for Loan Losses (Details 9) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Changes in accretable yield of loans acquired with deteriorated credit quality
Beginning Balance	$ (39,950)	$ (7,848)
Additions through acquisition	0	(37,555)
Reclasses from nonaccretable difference	(7,130)	(7,568)
Accretion	13,588	13,021
Ending Balance	(32,433)	(39,950)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses, Decreases	1,059
Impaired Covered Loans
Changes in accretable yield of loans acquired with deteriorated credit quality
Beginning Balance	(1)	(13)
Additions through acquisition	0	0
Reclasses from nonaccretable difference	(104)	(115)
Accretion	104	127
Ending Balance	(1)	(1)
Other Covered Loans
Changes in accretable yield of loans acquired with deteriorated credit quality
Beginning Balance	(3,758)	(6,705)
Additions through acquisition	0	0
Reclasses from nonaccretable difference	(6,343)	(6,741)
Accretion	7,478	9,688
Ending Balance	(2,623)	(3,758)
Not Covered Loans
Changes in accretable yield of loans acquired with deteriorated credit quality
Beginning Balance	(36,191)	(1,130)
Additions through acquisition	0	(37,555)
Reclasses from nonaccretable difference	(683)	(712)
Accretion	6,006	3,206
Ending Balance	(29,809)	(36,191)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses, Decreases	$ 1,059

The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans accounted for as available-for-sale debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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- Definition

Current period recognition of the accretion of the excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This element relates to loans accounted for as available-for-sale debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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- Definition

Increases in the aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans accounted for as available-for-sale debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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- Definition

Change in the estimate of cash flows expected to be collected, which results in an increase in accretable yield. This relates to a loan accounted for as an available-for-sale debt security, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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- Definition

Amount of reduction in the reserve for loans impairments as a result of current information and events which result in it being probable that estimated cash flows will be significantly higher than previously expected or because actual cash flows are significantly greater than cash flows previously expected for loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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