Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Condensed Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 13,580	$ 14,701	$ 19,178	$ 29,214
Other comprehensive income (loss):
Foreign currency translation adjustments	(3,534)	1,253	(487)	5,837
Unrealized gain (loss) on investments, net of tax	(565)	525	81	754
Other	27	20	25	33
Comprehensive income	9,508	16,499	18,797	35,838
Foreign currency translation adjustments	(10,161)		(10,161)		(9,674)
Unrealized loss on investments, net of tax	(3,246)		(3,246)		(3,327)
Other	(424)		(424)		(449)
Accumulated other comprehensive loss	$ (13,831)		$ (13,831)		$ (13,450)