Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Assets [Abstract]
Interest bearing deposits - time		$ 8,560	$ 11,866
Trading securities		212	148
Securities available for sale		599,755	585,484
Federal Home Loan Bank and Federal Reserve Bank Stock		15,229	15,471
Liabilities [Abstract]
Other borrowings		11,797	11,954
Subordinated debentures		35,569	35,569
Reciprocal deposits included in deposits with no stated maturity		12,400	11,800
Reciprocal deposits included in deposits with stated maturity		37,000	38,400
Recorded Book Balance [Member]
Assets [Abstract]
Cash and due from banks		34,542	54,260
Interest bearing deposits		26,488	31,523
Interest bearing deposits - time		8,560	11,866
Trading securities		212	148
Securities available for sale		599,755	585,484
Federal Home Loan Bank and Federal Reserve Bank Stock		15,229	15,471
Net loans and loans held for sale		1,591,123	1,520,346
Accrued interest receivable		6,767	6,565
Derivative financial instruments		3,307	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,687,965	1,659,743
Deposits with stated maturity	[1]	440,327	426,220
Other borrowings		11,797	11,954
Subordinated debentures		35,569	35,569
Accrued interest payable		536	466
Derivative financial instruments		2,785	619
Fair Value [Member]
Assets [Abstract]
Cash and due from banks		34,542	54,260
Interest bearing deposits		26,488	31,523
Interest bearing deposits - time		8,600	11,858
Trading securities		212	148
Securities available for sale		599,755	585,484
Net loans and loans held for sale		1,566,760	1,472,613
Accrued interest receivable		6,767	6,565
Derivative financial instruments		3,307	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,687,965	1,659,743
Deposits with stated maturity	[1]	439,916	423,776
Other borrowings		13,152	13,448
Subordinated debentures		22,445	23,069
Accrued interest payable		536	466
Derivative financial instruments		2,785	619
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and due from banks		34,542	54,260
Interest bearing deposits		26,488	31,523
Interest bearing deposits - time		0	0
Trading securities		212	148
Securities available for sale		0	0
Net loans and loans held for sale		0	0
Accrued interest receivable		3	5
Derivative financial instruments		0	0
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,687,965	1,659,743
Deposits with stated maturity	[1]	0	0
Other borrowings		0	0
Subordinated debentures		0	0
Accrued interest payable		18	21
Derivative financial instruments		0	0
Significant Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Cash and due from banks		0	0
Interest bearing deposits		0	0
Interest bearing deposits - time		8,600	11,858
Trading securities		0	0
Securities available for sale		599,755	585,484
Net loans and loans held for sale		31,713	27,866
Accrued interest receivable		2,178	1,969
Derivative financial instruments		3,307	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	0	0
Deposits with stated maturity	[1]	439,916	423,776
Other borrowings		13,152	13,448
Subordinated debentures		22,445	23,069
Accrued interest payable		518	445
Derivative financial instruments		2,785	619
Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Cash and due from banks		0	0
Interest bearing deposits		0	0
Interest bearing deposits - time		0	0
Trading securities		0	0
Securities available for sale		0	0
Net loans and loans held for sale		1,535,047	1,444,747
Accrued interest receivable		4,586	4,591
Derivative financial instruments		0	0
Liabilities [Abstract]
Deposits with no stated maturity	[1]	0	0
Deposits with stated maturity	[1]	0	0
Other borrowings		0	0
Subordinated debentures		0	0
Accrued interest payable		0	0
Derivative financial instruments		$ 0	$ 0

[1] Deposits with no stated maturity include reciprocal deposits with a recorded book balance of $12.4 million and $11.8 million at June 30, 2016 and December 31, 2015, respectively. Deposits with a stated maturity include reciprocal deposits with a recorded book balance of $37.0 million and $38.4 million at June 30, 2016 and December 31, 2015, respectively.