Summary of Significant Accounting Policies (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Activity of accumulated comprehensive income (loss)
Beginning Balance			$ (50)	$ (10)	$ (10)
Unrealized gain (loss) on investments, net of taxes	638	(62)	681	(81)	(42)
Unrealized gain (loss) on currency translation	(1)	1	(5)		2
Ending Balance	$ 626		$ 626		$ (50)