Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balances at Dec. 31, 2011	$ 167,610	$ 12,594	$ 95,039	$ 49,434	$ 10,543
Balances (in shares) at Dec. 31, 2011		12,594,258
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	24,055			24,055
Other Comprehensive Income (Loss)	(192)				(192)
Cash Dividends ($.56, $.60, $.64 per share)	(7,068)			(7,068)
Issuance of Common Stock for:
Exercise of Stock Options (in shares)		7,278
Exercise of Stock Options	37	8	29
Restricted Share Grants (in shares)		35,120
Restricted Share Grants	628	35	593
Employee Stock Purchase Plan	(67)		(67)
Income Tax Benefit from Restricted Share Grant	23		23
Balances at Dec. 31, 2012	185,026	12,637	95,617	66,421	10,351
Balances (in shares) at Dec. 31, 2012		12,636,656
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	25,413			25,413
Other Comprehensive Income (Loss)	(15,614)				(15,614)
Cash Dividends ($.56, $.60, $.64 per share)	(7,670)			(7,670)
Issuance of Common Stock for:
Exercise of Stock Options (in shares)		1,999
Exercise of Stock Options	20	2	18
Acquisition of United Commerce Bancorp (in shares)		502,560
Acquisition of United Commerce Bancorp	12,574	503	12,071
Restricted Share Grants (in shares)		32,578
Restricted Share Grants	329	32	297
Employee Stock Purchase Plan	(9)		(9)
Income Tax Benefit from Restricted Share Grant	28		28
Balances at Dec. 31, 2013	200,097	13,174	108,022	84,164	(5,263)
Balances (in shares) at Dec. 31, 2013		13,173,793
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	28,344			28,344
Other Comprehensive Income (Loss)	8,153				8,153
Cash Dividends ($.56, $.60, $.64 per share)	(8,450)			(8,450)
Issuance of Common Stock for:
Exercise of Stock Options (in shares)	17,000	6,640
Exercise of Stock Options	50	7	43
Restricted Share Grants (in shares)		35,367
Restricted Share Grants	627	35	592
Employee Stock Purchase Plan	(37)		(37)
Income Tax Benefit from Restricted Share Grant	40		40
Balances at Dec. 31, 2014	$ 228,824	$ 13,216	$ 108,660	$ 104,058	$ 2,890
Balances (in shares) at Dec. 31, 2014		13,215,800