Fair Values of Financial Instruments (Details) (USD $)	Mar. 31, 2013		Dec. 31, 2012
Assets [Abstract]
Cash and due from banks	$ 51,489,000		$ 55,487,000
Securities available for sale	283,934,000		208,413,000
Liabilities [Abstract]
Subordinated debentures	50,175,000		50,175,000
Reciprocal deposits included in deposits with no stated maturity	3,900,000		1,200,000
Reciprocal deposits included in deposits with stated maturity	42,000,000		32,000,000
Recorded Book Balance [Member]
Assets [Abstract]
Cash and due from banks	51,489,000		55,487,000
Interest bearing deposits	170,141,000		124,295,000
Interest bearing deposits - time	6,973,000
Trading securities	201,000		110,000
Securities available for sale	283,934,000		208,413,000
Federal Home Loan Bank and Federal Reserve Bank Stock	20,838,000		20,838,000
Net loans and loans held for sale	1,387,651,000		1,425,643,000
Accrued interest receivable	6,154,000		5,814,000
Derivative financial instruments	1,159,000		1,368,000
Liabilities [Abstract]
Deposits with no stated maturity	1,427,613,000	[1]	1,360,609,000	[1]
Deposits with stated maturity	423,180,000	[1]	418,928,000	[1]
Other borrowings	17,630,000		17,625,000
Subordinated debentures	50,175,000		50,175,000
Accrued interest payable	7,782,000		7,197,000
Derivative financial instruments	2,338,000		1,320,000
Fair Value Measurements [Member]
Assets [Abstract]
Cash and due from banks	51,489,000		55,487,000
Interest bearing deposits	170,141,000		124,295,000
Interest bearing deposits - time	6,973,000
Trading securities	201,000		110,000
Securities available for sale	283,934,000		208,413,000
Net loans and loans held for sale	1,338,104,000		1,400,385,000
Accrued interest receivable	6,154,000		5,814,000
Derivative financial instruments	1,159,000		1,368,000
Liabilities [Abstract]
Deposits with no stated maturity	1,427,613,000	[1]	1,360,609,000	[1]
Deposits with stated maturity	425,026,000	[1]	420,374,000	[1]
Other borrowings	21,230,000		21,463,000
Subordinated debentures	46,719,000		42,235,000
Accrued interest payable	7,782,000		7,197,000
Derivative financial instruments	2,338,000		1,320,000
Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member]
Assets [Abstract]
Cash and due from banks	51,489,000		55,487,000
Interest bearing deposits	170,141,000		124,295,000
Interest bearing deposits - time	0
Trading securities	201,000		110,000
Securities available for sale	0		0
Net loans and loans held for sale	0		0
Accrued interest receivable	129,000		102,000
Derivative financial instruments	0		0
Liabilities [Abstract]
Deposits with no stated maturity	1,427,613,000	[1]	1,360,609,000	[1]
Deposits with stated maturity	0	[1]	0	[1]
Other borrowings	0		0
Subordinated debentures	8,801,000		7,956,000
Accrued interest payable	3,199,000		2,942,000
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	6,973,000
Trading securities	0		0
Securities available for sale	283,934,000		208,413,000
Net loans and loans held for sale	37,554,000		50,779,000
Accrued interest receivable	1,130,000		934,000
Derivative financial instruments	1,159,000		1,368,000
Liabilities [Abstract]
Deposits with no stated maturity	0	[1]	0	[1]
Deposits with stated maturity	425,026,000	[1]	420,374,000	[1]
Other borrowings	21,230,000		21,463,000
Subordinated debentures	37,918,000		34,279,000
Accrued interest payable	4,583,000		4,255,000
Derivative financial instruments	834,000		861,000
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
Trading securities	0		0
Securities available for sale	0		0
Net loans and loans held for sale	1,300,550,000		1,349,606,000
Accrued interest receivable	4,895,000		4,778,000
Derivative financial instruments	0		0
Liabilities [Abstract]
Deposits with no stated maturity	0	[1]	0	[1]
Deposits with stated maturity	0	[1]	0	[1]
Other borrowings	0		0
Subordinated debentures	0		0
Accrued interest payable	0		0
Derivative financial instruments	$ 1,504,000		$ 459,000

[1] Deposits with no stated maturity include reciprocal deposits with a recorded book balance of $3.9 million and $1.2 million at March 31, 2013 and December 31, 2012, respectively. Deposits with a stated maturity include reciprocal deposits with a recorded book balance of $42.0 million and $32.0 million at March 31, 2013 and December 31, 2012, respectively.