Fair Value of Assets and Liabilities, Part II (Details) - USD ($)		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Foreclosed Assets Held for Sale [Abstract]
Other real estate owned		$ 436,000		$ 477,000
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Assets, Fair Value Disclosure, Recurring		1,746,000		1,906,000
Financial Assets [Abstract]
Available-for-sale securities		500,577,000		518,848,000
Held-to-maturity Securities		112,161,000		85,208,000
Held-to-maturity Securities, Fair Value		113,112,000		85,737,000
Carrying Amount [Member]
Financial Assets [Abstract]
Cash and due from banks		52,581,000		115,292,000
Federal funds sold		491,000		492,000
Certificates of deposit investments		30,307,000		25,000,000
Available-for-sale securities		500,577,000		518,848,000
Held-to-maturity Securities		112,161,000		85,208,000
Loans held for sale		1,346,000		968,000
Loans net of allowance for loan losses		1,298,677,000		1,266,345,000
Interest receivable		7,299,000		8,085,000
Federal Reserve Bank stock		2,272,000		2,272,000
Federal Home Loan Bank stock		3,391,000		3,391,000
Financial Liabilities [Abstract]
Deposits		1,704,199,000		1,732,568,000
Securities sold under agreements to repurchase		131,099,000		128,842,000
Interest payable		385,000		356,000
Federal Home Loan Bank borrowings		40,000,000		20,000,000
Junior subordinated debentures		20,620,000		20,620,000
Fair Value [Member]
Financial Assets [Abstract]
Cash and due from banks		52,581,000		115,292,000
Federal funds sold		491,000		492,000
Certificates of deposit investments		30,391,000		25,056,000
Available-for-sale securities		500,577,000		518,848,000
Held-to-maturity Securities, Fair Value		113,112,000		85,737,000
Loans held for sale		1,346,000		968,000
Loans net of allowance for loan losses		1,297,118,000		1,265,126,000
Interest receivable		7,299,000		8,085,000
Federal Reserve Bank stock		2,272,000		2,272,000
Federal Home Loan Bank stock		3,391,000		3,391,000
Financial Liabilities [Abstract]
Deposits		1,704,869,000		1,732,463,000
Securities sold under agreements to repurchase		131,125,000		128,843,000
Interest payable		385,000		356,000
Federal Home Loan Bank borrowings		40,979,000		20,422,000
Junior subordinated debentures		13,223,000		13,207,000
Fair Value, Measurements, Nonrecurring [Member] | Carrying Amount [Member]
Foreclosed Assets Held for Sale [Abstract]
Other real estate owned		436,000
Fair Value, Measurements, Nonrecurring [Member] | Fair Value [Member]
Foreclosed Assets Held for Sale [Abstract]
Other real estate owned		89,000
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets [Abstract]
Cash and due from banks		52,581,000		115,292,000
Federal funds sold		491,000		492,000
Certificates of deposit investments		0		0
Available-for-sale securities		83,000		64,000
Held-to-maturity Securities, Fair Value		0		0
Loans held for sale		0		0
Loans net of allowance for loan losses		0		0
Interest receivable		0		0
Federal Reserve Bank stock		0		0
Federal Home Loan Bank stock		0		0
Financial Liabilities [Abstract]
Deposits		0		0
Securities sold under agreements to repurchase		0		0
Interest payable		0		0
Federal Home Loan Bank borrowings		0		0
Junior subordinated debentures		0		0
Significant Other Observable Inputs (Level 2)
Financial Assets [Abstract]
Cash and due from banks		0		0
Federal funds sold		0		0
Certificates of deposit investments		30,391,000		25,056,000
Available-for-sale securities		498,748,000		516,878,000
Held-to-maturity Securities, Fair Value		113,112,000		85,737,000
Loans held for sale		1,346,000		968,000
Loans net of allowance for loan losses		0		0
Interest receivable		7,299,000		8,085,000
Federal Reserve Bank stock		2,272,000		2,272,000
Federal Home Loan Bank stock		3,391,000		3,391,000
Financial Liabilities [Abstract]
Deposits		1,454,392,000		1,489,130,000
Securities sold under agreements to repurchase		131,125,000		128,843,000
Interest payable		385,000		356,000
Federal Home Loan Bank borrowings		40,979,000		20,422,000
Junior subordinated debentures		13,223,000		13,207,000
Significant Unobservable Inputs (Level 3)
Financial Assets [Abstract]
Cash and due from banks		0		0
Federal funds sold		0		0
Certificates of deposit investments		0		0
Available-for-sale securities		1,746,000		1,906,000
Held-to-maturity Securities, Fair Value		0		0
Loans held for sale		0		0
Loans net of allowance for loan losses		1,297,118,000		1,265,126,000
Interest receivable		0		0
Federal Reserve Bank stock		0		0
Federal Home Loan Bank stock		0		0
Financial Liabilities [Abstract]
Deposits		250,477,000		243,333,000
Securities sold under agreements to repurchase		0		0
Interest payable		0		0
Federal Home Loan Bank borrowings		0		0
Junior subordinated debentures		$ 0		0
Trust preferred securities | Significant Unobservable Inputs (Level 3) | Discounted Cash Flow [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount rate (in hundredths)		11.50%	11.40%
Constant prepayment rate (in hundredths)	[1]	1.30%	1.30%
Cumulative projected prepayments (in hundredths)		23.60%	23.60%
Probability of default (in hundredths)		0.40%	0.40%
Loss severity (in hundredths)		97.30%	97.30%
Projected cures given deferral (in hundredths)		100.00%	100.00%
Impaired loans (collateral dependent) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 977,000		294,000
Impaired loans (collateral dependent) | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		0		0
Impaired loans (collateral dependent) | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 0		0
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3) | Minimum [Member] | Third Party Valuations [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount to reflect realizable value (in hundredths)		0.00%	0.00%
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3) | Maximum [Member] | Third Party Valuations [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount to reflect realizable value (in hundredths)		40.00%	40.00%
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3) | Weighted Average [Member] | Third Party Valuations [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount to reflect realizable value (in hundredths)		20.00%	20.00%
Impaired loans (collateral dependent) | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 977,000		294,000
Assets Held-for-sale [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		89,000		423,000
Assets Held-for-sale [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		0		0
Assets Held-for-sale [Member] | Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 0		0
Assets Held-for-sale [Member] | Significant Unobservable Inputs (Level 3) | Minimum [Member] | Third Party Valuations [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount to reflect realizable value less estimated selling costs (in hundredths)		0.00%	0.00%
Assets Held-for-sale [Member] | Significant Unobservable Inputs (Level 3) | Maximum [Member] | Third Party Valuations [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount to reflect realizable value less estimated selling costs (in hundredths)		40.00%	40.00%
Assets Held-for-sale [Member] | Significant Unobservable Inputs (Level 3) | Weighted Average [Member] | Third Party Valuations [Member]
Assets Measured On Recurring And Nonrecurring Basis Valuation Techniques [Abstract]
Discount to reflect realizable value (in hundredths)			35.00%
Discount to reflect realizable value less estimated selling costs (in hundredths)		35.00%
Assets Held-for-sale [Member] | Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 89,000		$ 423,000

[1] Every five years