CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
BALANCE at Dec. 31, 2010	$ 21,124	$ 229,722	$ 21,175	$ 539	$ 272,560
BALANCE (in shares) at Dec. 31, 2010		19,286
Net income	0	0	33,777	0	33,777
Other comprehensive income, net of tax:	0	0	0	6,898	6,898
Redemption of stock pursuant to stock plans	0	(531)	0	0	(531)
Redemption of stock pursuant to stock plans (in shares)		(55)
Activity in deferred compensation plan	0	(27)	0	0	(27)
Activity in deferred compensation plan (in shares)		(3)
Issuance of common stock-stock options	0	80	0	0	80
Issuance of common stock-stock options (in shares)		7
Issuance of common stock-restricted stock	0	0	0	0	0
Issuance of common stock-restricted stock (in shares)		64
Stock based compensation expense	0	1,899	0	0	1,899
Tax adjustment associated with stock plans	0	(159)	0	0	(159)
Fractional share payment	0	(18)	0	0	(18)
Fractional share payment (in shares)		(1)
BALANCE at Dec. 31, 2011	21,124	230,966	54,952	7,437	314,479
BALANCE (in shares) at Dec. 31, 2011		19,298
Net income	0	0	11,823	0	11,823
Other comprehensive income, net of tax:	0	0	0	1,238	1,238
Redemption of stock pursuant to stock plans	0	(499)	0	0	(499)
Redemption of stock pursuant to stock plans (in shares)		(38)
Activity in deferred compensation plan	0	52	0	0	52
Activity in deferred compensation plan (in shares)		(1)
Issuance of common stock-stock options	0	70	0	0	70
Issuance of common stock-stock options (in shares)		6			(6,055)
Issuance of common stock-restricted stock	0	0	0	0	0
Issuance of common stock-restricted stock (in shares)		30
Stock based compensation expense	0	792	0	0	792
Tax adjustment associated with stock plans	0	62	0	0	62
BALANCE at Jun. 30, 2012	$ 21,124	$ 231,443	$ 66,775	$ 8,675	$ 328,017
BALANCE (in shares) at Jun. 30, 2012		19,295