Comprehensive Loss (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	$ 2,689	$ 2,745
Other comprehensive income (loss) before reclassifications	(141)	(197)
Net current-period other comprehensive income	(141)	(197)
Balance at the end of the period	2,548	2,548
Amounts reclassified from other comprehensive income	0	0
Unrealized Gain (Loss) on Marketable Securities, net of tax
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	102	156
Other comprehensive income (loss) before reclassifications	(140)	(194)
Net current-period other comprehensive income	(140)	(194)
Balance at the end of the period	(38)	(38)
Foreign Currency Items
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	2,587	2,589
Other comprehensive income (loss) before reclassifications	(1)	(3)
Net current-period other comprehensive income	(1)	(3)
Balance at the end of the period	$ 2,586	$ 2,586