Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net income	$ 43,227	$ 50,617
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	672	2,606
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	455	1,097
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(175)	(420)
Other Comprehensive Income (Loss), Net of Tax	952	3,283
Comprehensive income	$ 44,179	$ 53,900