CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common stock	Additional Paid-in capital	Retained Earnings	Accumulated Other Comprehensive Income (loss)	Non-controlling interest
Balance at Dec. 31, 2008	$ 547,070	$ 1,522	$ 365,362	$ 232,321	$ (54,616)	$ 2,481
Balance (in shares) at Dec. 31, 2008		152,155,213
Increase (Decrease) in Stockholders' Equity
Stock-based compensation from option awards	18,209		18,209
Stock options exercised	3,398	20	3,379
Stock options exercised (in shares)	2,072,533	2,072,533
Foreign currency translation adjustment	(3,795)				(3,812)	17
Net income (loss)	103,019			100,389		2,630
Dividends declared	(4,078)					(4,078)
Balance at Dec. 31, 2009	663,824	1,542	386,950	332,710	(58,428)	1,050
Balance (in shares) at Dec. 31, 2009		154,227,746
Increase (Decrease) in Stockholders' Equity
Stock-based compensation from option awards	29,260		29,260
Stock options exercised	42,812	27	42,785
Stock options exercised (in shares)	2,728,000	2,728,000
Foreign currency translation adjustment	(5,553)				(5,635)	82
Acquisition of non-controlling interest	(1,508)		(1,474)			(34)
Net income (loss)	151,032			145,731		5,301
Dividends declared	(85,226)			(80,444)		(4,782)
Balance at Dec. 31, 2010	794,641	1,569	457,521	397,997	(64,063)	1,617
Balance (in shares) at Dec. 31, 2010		156,955,746
Increase (Decrease) in Stockholders' Equity
Stock-based compensation from option awards	17,193		17,193
Stock options exercised	5,352	4	5,348
Stock options exercised (in shares)	364,324	364,324
Foreign currency translation adjustment	(47,698)				(47,691)	(7)
Acquisition of non-controlling interest	2,206		1,907			299
Net income (loss)	60,516			53,117		7,399
Dividends declared	(135,002)			(128,930)		(6,072)
Balance at Dec. 31, 2011	$ 697,208	$ 1,573	$ 481,969	$ 322,184	$ (111,754)	$ 3,236
Balance (in shares) at Dec. 31, 2011		157,320,070