Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 2,878	$ 19,010	$ 51,959	$ 79,758	$ 53,381
Other comprehensive income (loss):
Foreign currency translation adjustments			(6,903)	(2,318)	4,393
Unrealized loss on investments, net of tax			526	536	924
Other			(111)	(187)	(125)
Comprehensive income			45,471	77,789	58,573
Foreign currency translation losses	(9,674)	(2,771)	(9,674)	(2,771)
Unrealized loss on investments, net of tax	(3,327)	(3,853)	(3,327)	(3,853)
Other	(449)	(338)	(449)	(338)
Accumulated other comprehensive loss	$ (13,450)	$ (6,962)	$ (13,450)	$ (6,962)