Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Assets [Abstract]
Interest bearing deposits - time		$ 10,178	$ 11,866
Trading securities		136	148
Securities available for sale		589,500	585,484
Federal Home Loan Bank and Federal Reserve Bank Stock		15,600	15,471
Liabilities [Abstract]
Other borrowings		11,953	11,954
Subordinated debentures		35,569	35,569
Reciprocal deposits included in deposits with no stated maturity		14,200	11,800
Reciprocal deposits included in deposits with stated maturity		36,100	38,400
Recorded Book Balance [Member]
Assets [Abstract]
Cash and due from banks		41,790	54,260
Interest bearing deposits		102,919	31,523
Interest bearing deposits - time		10,178	11,866
Trading securities		136	148
Securities available for sale		589,500	585,484
Federal Home Loan Bank and Federal Reserve Bank Stock		15,600	15,471
Net loans and loans held for sale		1,544,503	1,520,346
Accrued interest receivable		6,855	6,565
Derivative financial instruments		2,584	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,704,515	1,659,743
Deposits with stated maturity	[1]	450,191	426,220
Other borrowings		11,953	11,954
Subordinated debentures		35,569	35,569
Accrued interest payable		562	466
Derivative financial instruments		1,952	619
Fair Value [Member]
Assets [Abstract]
Cash and due from banks		41,790	54,260
Interest bearing deposits		102,919	31,523
Interest bearing deposits - time		10,214	11,858
Trading securities		136	148
Securities available for sale		589,500	585,484
Net loans and loans held for sale		1,513,641	1,472,613
Accrued interest receivable		6,855	6,565
Derivative financial instruments		2,584	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,704,515	1,659,743
Deposits with stated maturity	[1]	449,221	423,776
Other borrowings		13,425	13,448
Subordinated debentures		22,526	23,069
Accrued interest payable		562	466
Derivative financial instruments		1,952	619
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and due from banks		41,790	54,260
Interest bearing deposits		102,919	31,523
Interest bearing deposits - time		0	0
Trading securities		136	148
Securities available for sale		0	0
Net loans and loans held for sale		0	0
Accrued interest receivable		0	5
Derivative financial instruments		0	0
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,704,515	1,659,743
Deposits with stated maturity	[1]	0	0
Other borrowings		0	0
Subordinated debentures		0	0
Accrued interest payable		21	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		10,214	11,858
Trading securities		0	0
Securities available for sale		589,500	585,484
Net loans and loans held for sale		28,016	27,866
Accrued interest receivable		2,300	1,969
Derivative financial instruments		2,584	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	0	0
Deposits with stated maturity	[1]	449,221	423,776
Other borrowings		13,425	13,448
Subordinated debentures		22,526	23,069
Accrued interest payable		541	445
Derivative financial instruments		1,952	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		1,485,625	1,444,747
Accrued interest receivable		4,555	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 $14.2 million and $11.8 million at March 31, 2016 and December 31, 2015, respectively. Deposits with a stated maturity include reciprocal deposits with a recorded book balance of $36.1 million and $38.4 million at March 31, 2016 and December 31, 2015, respectively.