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, 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	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	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
Increase (Decrease) in Stockholders' Equity
Stock-based compensation from option awards	5,349		5,349
Stock options exercised	4,616	9	4,607
Stock options exercised (in shares)	840,649	840,649
Foreign currency translation adjustment	43,616				43,567	49
Net income	99,816			93,063		6,753
Dividends declared	(87,679)			(82,244)		(5,435)
Balance at Dec. 31, 2012	$ 762,926	$ 1,582	$ 491,925	$ 333,003	$ (68,187)	$ 4,603
Balance (in shares) at Dec. 31, 2012		158,160,719