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 six months ended June 30, 2011			20,352		20,352
Issuance of 55,749 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		2,209			2,209
Issuance of 47,506 deferred stock units relating to 2010 compensation		1,100			1,100
Balance - at Jun. 30, 2011	$ 247	$ 83,799	$ 212,419	$ (28,841)	$ 267,624