Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Assets [Abstract]
Interest bearing deposits - time		$ 7,233	$ 11,866
Trading securities		152	148
Securities available for sale		603,112	585,484
Federal Home Loan Bank and Federal Reserve Bank Stock		15,507	15,471
Liabilities [Abstract]
Other borrowings		11,527	11,954
Subordinated debentures		35,569	35,569
Reciprocal deposits included in deposits with no stated maturity		9,300	11,800
Reciprocal deposits included in deposits with stated maturity		37,300	38,400
Recorded Book Balance [Member]
Assets [Abstract]
Cash and due from banks		38,610	54,260
Interest bearing deposits		75,706	31,523
Interest bearing deposits - time		7,233	11,866
Trading securities		152	148
Securities available for sale		603,112	585,484
Federal Home Loan Bank and Federal Reserve Bank Stock		15,507	15,471
Net loans and loans held for sale		1,623,319	1,520,346
Accrued interest receivable		6,973	6,565
Derivative financial instruments		3,388	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,743,864	1,659,743
Deposits with stated maturity	[1]	463,096	426,220
Other borrowings		11,527	11,954
Subordinated debentures		35,569	35,569
Accrued interest payable		630	466
Derivative financial instruments		2,508	619
Fair Value [Member]
Assets [Abstract]
Cash and due from banks		38,610	54,260
Interest bearing deposits		75,706	31,523
Interest bearing deposits - time		7,272	11,858
Trading securities		152	148
Securities available for sale		603,112	585,484
Net loans and loans held for sale		1,601,113	1,472,613
Accrued interest receivable		6,973	6,565
Derivative financial instruments		3,388	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,743,864	1,659,743
Deposits with stated maturity	[1]	462,297	423,776
Other borrowings		12,702	13,448
Subordinated debentures		22,223	23,069
Accrued interest payable		630	466
Derivative financial instruments		2,508	619
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and due from banks		38,610	54,260
Interest bearing deposits		75,706	31,523
Interest bearing deposits - time		0	0
Trading securities		152	148
Securities available for sale		0	0
Net loans and loans held for sale		0	0
Accrued interest receivable		2	5
Derivative financial instruments		0	0
Liabilities [Abstract]
Deposits with no stated maturity	[1]	1,743,864	1,659,743
Deposits with stated maturity	[1]	0	0
Other borrowings		0	0
Subordinated debentures		0	0
Accrued interest payable		17	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		7,272	11,858
Trading securities		0	0
Securities available for sale		603,112	585,484
Net loans and loans held for sale		38,008	27,866
Accrued interest receivable		2,438	1,969
Derivative financial instruments		3,388	1,238
Liabilities [Abstract]
Deposits with no stated maturity	[1]	0	0
Deposits with stated maturity	[1]	462,297	423,776
Other borrowings		12,702	13,448
Subordinated debentures		22,223	23,069
Accrued interest payable		613	445
Derivative financial instruments		2,508	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		1,563,105	1,444,747
Accrued interest receivable		4,533	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 $9.3 million and $11.8 million at September 30, 2016 and December 31, 2015, respectively. Deposits with a stated maturity include reciprocal deposits with a recorded book balance of $37.3 million and $38.4 million at September 30, 2016 and December 31, 2015, respectively.