CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN COMMON STOCK EQUITY (unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Treasury Stock [Member]	Other Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2010	$ 92,821	$ (48,436)	$ 94,462	$ (232)	$ 134,113	$ 272,728
Balance (in shares) at Dec. 31, 2010	15,470,217	(2,129,073)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					8,425	8,425
Other comprehensive income				133		133
Dividend reinvestment plan	98		263			361
Dividend reinvestment plan (in shares)	16,313
Share-based compensation:
Common & nonvested shares	28		(25)			3
Common & nonvested shares (in shares)	4,699
Performance share plans	36		(207)			(171)
Performance share plans (in shares)	5,987
Dividends declared:
Common					(6,143)	(6,143)
Cumulative non-redeemable preferred stock					(92)	(92)
Amortization of preferred stock issuance expense			4			4
Balance at Mar. 31, 2011	92,983	(48,436)	94,497	(99)	136,303	275,248
Balance (in shares) at Mar. 31, 2011	15,497,216	(2,129,073)
Balance at Dec. 31, 2011	93,613	(48,436)	96,040	(186)	127,123	268,154
Balance (in shares) at Dec. 31, 2011	15,602,091	(2,129,073)				13,473,018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					8,875	8,875
Other comprehensive income				1		1
Dividend reinvestment plan	43		212			255
Dividend reinvestment plan (in shares)	7,187
Stock options exercised	502		1,014			1,516
Stock options exercised (in shares)	83,770
Share-based compensation:
Common & nonvested shares			590			590
Performance share plans			56			56
Dividends declared:
Common					(3,100)	(3,100)
Cumulative non-redeemable preferred stock					(92)	(92)
Amortization of preferred stock expense			4			4
Balance at Mar. 31, 2012	$ 94,158	$ (48,436)	$ 97,916	$ (185)	$ 132,806	$ 276,259
Balance (in shares) at Mar. 31, 2012	15,693,048	(2,129,073)				13,563,975