CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Retained Earnings	Cost of Common Stock in Treasury	Accumulated Other Comprehensive Income (Loss), Net
Balance at Dec. 31, 2012	$ 558,655	$ 346,535	$ 223,715	$ (31,134)	$ 19,539
Increase (Decrease) in Shareholders' Equity
Net income	12,404		12,404
Other comprehensive income (loss)	(1,206)				(1,206)
Issuance of 61,978 and 148,627 common shares under stock based compensation awards, including related tax effects for the three months ended on March 31, 2014 and 2013, respectively	3,249		(281)	3,530
Cost of 48,607 and 24,800 shares of common stock acquired for treasury for the three months ended on March 31, 2014 and 2013, respectively	(566)			(566)
Common stock dividend ($0.17 and $0.17 per share for the three months ended on March 31, 2014 and 2013, respectively)	(4,174)		(4,174)
Balance at Mar. 31, 2013	568,362	346,535	231,664	(28,170)	18,333
Balance at Dec. 31, 2013	585,378	346,535	261,626	(29,364)	6,581
Increase (Decrease) in Shareholders' Equity
Net income	13,632		13,632
Other comprehensive income (loss)	1,907				1,907
Issuance of 61,978 and 148,627 common shares under stock based compensation awards, including related tax effects for the three months ended on March 31, 2014 and 2013, respectively	1,237		(243)	1,480
Cost of 48,607 and 24,800 shares of common stock acquired for treasury for the three months ended on March 31, 2014 and 2013, respectively	(1,401)			(1,401)
Common stock dividend ($0.17 and $0.17 per share for the three months ended on March 31, 2014 and 2013, respectively)	(4,167)		(4,167)
Balance at Mar. 31, 2014	$ 596,586	$ 346,535	$ 270,848	$ (29,285)	$ 8,488