Consolidated Statements of Comprehensive Loss - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Consolidated Statements of Comprehensive Loss      
Net loss $ (89,782) $ (47,492) $ (24,838)
Other comprehensive loss:      
Unrealized loss on available-for-sale marketable securities, net of tax (15)    
Comprehensive loss $ (89,797) $ (47,492) $ (24,838)