CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock
Balance at Dec. 31, 2010	$ 328,523	$ 391	$ 281,119	$ (1,971)	$ 91,069	$ (42,085)
Balance (in shares) at Dec. 31, 2010		39,063,000				(3,295,000)
Increase (Decrease) in Stockholders' Equity
Net income	5,855				5,855
Foreign currency translation adjustment	437			437
Tax benefit from share-based compensation	320		320
Common stock issued under share-based compensation plans	2,279	4	(1,590)			3,865
Common stock issued under share-based compensation plans (in shares)		431,000				299,000
Common stock repurchased under share-based compensation plans	(900)					(900)
Common stock repurchased under share-based compensation plans (in shares)	(66,290)					(66,000)
Share repurchases (Note 9)	(9,958)					(9,958)
Share repurchases (Note 9) (in shares)						(745,000)
Dividends declared ($0.115 per share and $0.105 per share for the six months period ended June 30, 2012 and 2011, respectively) (Note 9)	(3,718)				(3,718)
Share-based compensation	3,517		3,517
Balance at Jun. 30, 2011	326,355	395	283,366	(1,534)	93,206	(49,078)
Balance (in shares) at Jun. 30, 2011		39,494,000				(3,807,000)
Balance at Dec. 31, 2011	332,919	395	286,869	(1,987)	95,849	(48,207)
Balance (in shares) at Dec. 31, 2011		39,494,000				(3,740,000)
Increase (Decrease) in Stockholders' Equity
Net income	7,196				7,196
Foreign currency translation adjustment	87			87
Tax benefit from share-based compensation	(266)		(266)
Common stock issued under share-based compensation plans	130	4	(498)			624
Common stock issued under share-based compensation plans (in shares)		430,000				49,000
Common stock repurchased under share-based compensation plans	(2,045)					(2,045)
Common stock repurchased under share-based compensation plans (in shares)	(169,093)					(169,000)
Share repurchases (Note 9)	(1,444)					(1,444)
Share repurchases (Note 9) (in shares)						(120,000)
Dividends declared ($0.115 per share and $0.105 per share for the six months period ended June 30, 2012 and 2011, respectively) (Note 9)	(4,145)				(4,145)
Share-based compensation	3,403		3,403
Balance at Jun. 30, 2012	$ 335,835	$ 399	$ 289,508	$ (1,900)	$ 98,900	$ (51,072)
Balance (in shares) at Jun. 30, 2012		39,924,000				(3,980,000)