Quarterly Financial Results (unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interim Period, Costs Not Allocable [Line Items]
Revenue	$ 35,249	$ 33,260	$ 33,964	$ 29,784	$ 29,222	$ 26,696	$ 25,509	$ 24,519	$ 132,257	$ 105,946	$ 83,417
Gross Profit	26,077	25,898	25,004	22,528	22,064	20,252	19,232	19,116	32,750	25,282	18,746
Operating expenses	27,217	28,116	27,524	27,018	27,761	27,185	24,819	22,790	109,875	102,555	83,087
Net loss	(3,412)	(8,990)	5,670	(9,335)	(6,518)	(5,857)	(6,696)	(16,703)	(16,068)	(35,774)	(28,730)
Basic loss per share	$ (0.05)	$ (0.14)	$ 0.09	$ (0.16)	$ (0.10)	$ (0.10)	$ (0.11)	$ (0.29)	$ (0.26)	$ (0.60)	$ (0.51)
Diluted loss per share	$ (0.05)	$ (0.14)	$ 0.09	$ (0.16)	$ (0.10)	$ (0.10)	$ (0.11)	$ (0.29)
Asia Pacific
Interim Period, Costs Not Allocable [Line Items]
Revenue										$ 5,591	$ 3,149