Accumulated Other Comprehensive Income Schedule of Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Loss [Roll Forward]
Balance as of January 1, 2013, foreign currency translation			$ (2,354)
Balance as of January 1, 2013, net unrealized gain (loss) on investments			714
Balance as of January 1, 2013, total accumulated other comprehensive income			(1,640)
Other comprehensive loss, foreign currency translation	(3,746)	(3,702)	(7,760)	(3,030)
Other comprehensive loss, net of tax, net unrealized gain (loss) on investments	(1,626)	(99)	(1,555)	181
Other comprehensive loss, net of tax, total other comprehensive income	(5,372)	(3,801)	(9,315)	(2,849)
Balance as of June 30, 2013, foreign currency translation	(10,114)		(10,114)
Balance as of June 30, 2013, net unrealized gain (loss) on investments	(841)		(841)
Balance as of June 30, 2013, total accumulated other comprehensive income	$ (10,955)		$ (10,955)