Unaudited Condensed Consolidated Statement of Stockholders' Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Deferred Compensation Expense [Member]	Total
Balance at December 31, 2012 at Dec. 31, 2012	$ 266	$ 389,881	$ 579,062	$ 59,875	$ (11,533)	$ 10,331	$ 1,027,882
Balance at December 31, 2012 (in Shares) at Dec. 31, 2012					(367,000)
Net income			45,016				45,016
Dividends			(19,817)				(19,817)
Issuance of common stock	3	8,474					8,477
Treasury stock					(11,359)		(11,359)
Treasury stock (in Shares)					(320)
Deferred compensation plan		185			2,771	(2,771)	185
Deferred compensation plan (in Shares)					63
Translation adjustment				(14,890)			(14,890)
Balance at September 30, 2013 at Sep. 30, 2013	$ 269	$ 398,540	$ 604,260	$ 44,986	$ (20,121)	$ 7,560	$ 1,035,494
Balance at September 30, 2013 (in Shares) at Sep. 30, 2013					(625,000)