Fair Value (Details 4) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Carrying amount and estimated fair value of financial instruments
Securities available-for-sale	$ 906,341us-gaap_AvailableForSaleSecurities	$ 897,053us-gaap_AvailableForSaleSecurities
Restricted Investments	16,404us-gaap_RestrictedInvestments	16,404us-gaap_RestrictedInvestments
Accrued interest receivable	11,381us-gaap_InterestReceivable	11,593us-gaap_InterestReceivable
Deposits	(2,463,949)us-gaap_Deposits	(2,457,197)us-gaap_Deposits
Fair Value, Inputs, Level 1 [Member]
Carrying amount and estimated fair value of financial instruments
Cash and Cash Equivalents, Fair Value Disclosure	21,024
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0
Securities available-for-sale	0	0
Loans Receivable, Fair Value Disclosure	0
FDIC Indemnification Asset
Accrued interest receivable	0
Deposits	0
Short-term borrowings	0
Federal Home Loan Bank advances	0
Accrued interest payable	0
Fair Value, Inputs, Level 2 [Member]
Carrying amount and estimated fair value of financial instruments
Cash and Cash Equivalents, Fair Value Disclosure	67,468	55,505
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	12,688	8,000
Securities available-for-sale	886,308	875,850
Loans Receivable, Fair Value Disclosure	0
FDIC Indemnification Asset		(74)
Accrued interest receivable	3,584
Deposits	(2,466,517)	(2,459,703)
Short-term borrowings	(28,462)	(48,015)
Federal Home Loan Bank advances	(13,454)	(13,605)
Accrued interest payable	(403)	(456)
Fair Value, Inputs, Level 3 [Member]
Carrying amount and estimated fair value of financial instruments
Cash and Cash Equivalents, Fair Value Disclosure	0
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	0
Securities available-for-sale	20,033	21,203
Loans Receivable, Fair Value Disclosure	1,793,291	1,810,885
FDIC Indemnification Asset
Accrued interest receivable	7,797	8,410
Deposits	0
Short-term borrowings	0
Federal Home Loan Bank advances	0
Accrued interest payable	0
Reported Value Measurement [Member]
Carrying amount and estimated fair value of financial instruments
Cash and Cash Equivalents, Fair Value Disclosure	88,492	78,102
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	12,688	8,000
Securities available-for-sale	906,341	897,053
Restricted Investments	16,404
Loans Receivable, Fair Value Disclosure	1,737,253	1,762,589
FDIC Indemnification Asset		(74)
Accrued interest receivable	11,381	11,593
Deposits	(2,463,949)	(2,457,197)
Short-term borrowings	(28,462)	(48,015)
Federal Home Loan Bank advances	(12,812)	(12,886)
Accrued interest payable	(403)	(456)
Estimate of Fair Value Measurement [Member]
Carrying amount and estimated fair value of financial instruments
Cash and Cash Equivalents, Fair Value Disclosure	88,492	78,102
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell, Fair Value Disclosure	12,688	8,000
Securities available-for-sale	906,341	897,053
Loans Receivable, Fair Value Disclosure	1,793,291	1,810,885
FDIC Indemnification Asset		(74)
Accrued interest receivable	11,381	11,593
Deposits	(2,466,517)	(2,459,703)
Short-term borrowings	(28,462)	(48,015)
Federal Home Loan Bank advances	(13,454)	(13,605)
Accrued interest payable	$ (403)	$ (456)

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

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The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

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Carrying amount of receivable assets originating from the indemnification agreement with the Federal Deposit Insurance Corporation (FDIC), in which the FDIC is to partially cover losses.

+ References

No definition available.

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Fair value portion of federal funds sold and securities borrowed or purchased under agreements to resell.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Amount of interest payable on debt, including, but not limited to, trade payables.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.15(a))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph a

-Article 7

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph 5

-Article 9

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 8

-Article 5

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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Glossary Loan

-URI http://asc.fasb.org/extlink&oid=6517073

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Investments which are not defined as or included in marketable (debt, equity, or other) securities whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet.

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.

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