Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Condensed Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 19,314	$ 19,867	$ 38,492	$ 49,081
Other comprehensive income (loss):
Foreign currency translation adjustments	715	(9,013)	228	(3,176)
Unrealized gain (loss) on investments, net of tax	270	(156)	351	598
Other		546	25	579
Comprehensive income	20,299	11,244	39,096	47,082
Foreign currency translation adjustments	(9,446)		(9,446)		(9,674)
Unrealized loss on investments, net of tax	(2,976)		(2,976)		(3,327)
Other	(424)		(424)		(449)
Accumulated other comprehensive loss	$ (12,846)		$ (12,846)		$ (13,450)