Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 272	$ 8,186	$ (4,407)	$ 37,198
Other comprehensive income (loss)
Unrealized gain (loss) on investments, net of taxes	638	(62)	681	(81)
Unrealized gain (loss) on currency translation	(1)	1	(5)
Other comprehensive income (loss)	637	(61)	676	(81)
Comprehensive income (loss)	$ 909	$ 8,125	$ (3,731)	$ 37,117