Condensed Consolidated Statement Of Stockholders' Equity (USD $) In Thousands	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance - at Dec. 31, 2010	$ 247	$ 79,986	$ 192,067	$ (28,841)	$ 243,459
Net income for the nine months ended September 30, 2011			25,971		25,971
Issuance of 63,290 shares of common stock pursuant to stock options and deferred stock units		416			416
Income tax benefit relating to issuance of common stock pursuant to stock options and deferred stock units		88			88
Stock-based compensation expense		3,352			3,352
Issuance of 47,506 deferred stock units relating to 2010 compensation		1,100			1,100
Purchase of 33,856 shares of treasury stock				(626)	(626)
Balance - at Sep. 30, 2011	$ 247	$ 84,942	$ 218,038	$ (29,467)	$ 273,760