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
Net income	$ 44,239	$ 47,921	$ 87,466	$ 98,538
Other comprehensive income:
Foreign currency translation adjustments	(3,702)	1,782	(3,030)	4,388
Change in unrealized (loss) gain on investments, net	(161)	1,580	294	2,677
Income tax benefit (expense) related to unrealized (loss) gain on investments, net	62	(605)	(113)	(1,025)
Other comprehensive (loss) income	(3,801)	2,757	(2,849)	6,040
Comprehensive income	$ 40,438	$ 50,678	$ 84,617	$ 104,578