Share Options - Non-cash Share-Based Compensation Expenses Related to Company's Equity-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 2,928	$ 1,205	$ 7,372	$ 3,354
Cost of Revenues
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	35	14	54	31
Research, Development and Clinical Trials
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	668	254	1,717	543
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	571	262	1,550	807
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 1,654	$ 675	$ 4,051	$ 1,973