Condensed Conslidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (12,389)	$ 7,355	$ (20,185)	$ (3,208)
Unrealized (losses) gains on securities:
Unrealized holding (losses) gains arising during period	(82)	7	(73)	106
Reclassification for recognized gain (loss) on marketable investment securities during the period	(2)	(3)	(2)	(3)
Net unrealized (loss) gain on marketable investment securities	(84)	4	(75)	103
Foreign currency translation gain (loss)	7	2	9	(5)
Other comprehensive (loss) income	(77)	6	(66)	98
Comprehensive (loss) income	$ (12,466)	$ 7,361	$ (20,251)	$ (3,110)