CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2009	$ 721	$ 2,043	$ 110,047	$ 3,651	$ 116,462
Balance (in shares) at Dec. 31, 2009	7,213,056
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income			18,392		18,392
Other comprehensive income (loss)				(5,067)	(5,067)
Repurchase of common stock	0	(91)			(91)
Repurchase of common stock (in shares)	(3,581)
Common stock issued under stock compensation plans, including tax benefit	6	709			715
Common stock issued under stock compensation plans, including tax benefit (in shares)	60,690
Issuance of common stock	144	32,218			32,362
Issuance of common stock (in shares)	1,437,500
Stock-based compensation		647			647
Cash dividends declared			(6,726)		(6,726)
Balance at Dec. 31, 2010	871	35,526	121,713	(1,416)	156,694
Balance (in shares) at Dec. 31, 2010	8,707,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income			19,457		19,457
Other comprehensive income (loss)				19,104	19,104
Repurchase of common stock	(1)	(184)			(185)
Repurchase of common stock (in shares)	(7,022)
Common stock issued under stock compensation plans, including tax benefit	9	1,409			1,418
Common stock issued under stock compensation plans, including tax benefit (in shares)	93,289
Stock-based compensation		756			756
Cash dividends declared			(7,897)		(7,897)
Balance at Dec. 31, 2011	879	37,507	133,273	17,688	189,347
Balance (in shares) at Dec. 31, 2011	8,793,932
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income			20,393		20,393
Other comprehensive income (loss)				(948)	(948)
Repurchase of common stock	(1)	(368)			(369)
Repurchase of common stock (in shares)	(13,150)
Common stock issued under stock compensation plans, including tax benefit	14	2,724			2,738
Common stock issued under stock compensation plans, including tax benefit (in shares)	145,604
Common stock issued under dividend reinvestment and stock purchase plan	8	1,998			2,006
Common stock issued under dividend reinvestment and stock purchase plan (in shares)	75,300
Stock-based compensation		782			782
Cash dividends declared			(8,579)		(8,579)
Balance at Dec. 31, 2012	$ 900	$ 42,643	$ 145,087	$ 16,740	$ 205,370
Balance (in shares) at Dec. 31, 2012	9,001,686