Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Condensed Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 5,598	$ 14,513
Other comprehensive income (loss):
Foreign currency translation adjustments	3,047	4,584
Unrealized gain on investments, net of tax	646	229
Other	(2)	13
Comprehensive income	9,289	19,339
Foreign currency translation adjustments	(6,627)		(9,674)
Unrealized loss on investments, net of tax	(2,681)		(3,327)
Other	(451)		(449)
Accumulated other comprehensive loss	$ (9,759)		$ (13,450)

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