Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
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 ($.60, $.64, $.68 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 (in shares) at Dec. 31, 2013		13,173,793
Balances at Dec. 31, 2013	200,097	$ 13,174	108,022	84,164	(5,263)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	28,344			28,344
Other Comprehensive Income (Loss)	8,153				8,153
Cash Dividends ($.60, $.64, $.68 per share)	(8,450)			(8,450)
Issuance of Common Stock for:
Exercise of Stock Options (in shares)		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 (in shares) at Dec. 31, 2014		13,215,800
Balances at Dec. 31, 2014	228,824	$ 13,216	108,660	104,058	2,890
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	30,064			30,064
Other Comprehensive Income (Loss)	922				922
Cash Dividends ($.60, $.64, $.68 per share)	$ (9,010)			(9,010)
Issuance of Common Stock for:
Exercise of Stock Options (in shares)	44,500	12,985
Exercise of Stock Options	$ 49	$ 13	36
Restricted Share Grants (in shares)		34,826
Restricted Share Grants	963	$ 35	928
Employee Stock Purchase Plan (in shares)		15,213
Employee Stock Purchase Plan	447	$ 15	432
Income Tax Benefit from Restricted Share Grant	89		89
Balances (in shares) at Dec. 31, 2015		13,278,824
Balances at Dec. 31, 2015	$ 252,348	$ 13,279	$ 110,145	$ 125,112	$ 3,812