XML 56 R36.htm IDEA: XBRL DOCUMENT v3.6.0.2
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Jan. 01, 2016
Dec. 31, 2013
Organization And Basis Of Presentation [Line Items]                          
Accumulated deficit $ (213,875,000)       $ (101,488,000)       $ (213,875,000) $ (101,488,000)      
Net loss (31,276,000) $ (29,031,000) $ (28,613,000) $ (23,467,000) (17,000,000) $ (18,126,000) $ 9,007,000 $ (3,502,000) $ (112,387,000) (29,621,000) $ (3,214,000)    
Cash and cash equivalents original maturity dates                 90 days or less        
Short-term investments maturity period description                 Short-term investments consist of debt securities classified as available-for-sale and have maturities greater than 90 days, but less than 365 days from the date of acquisition.        
Impairment loss of long lived assets                 $ 0        
Income tax benefit                   (29,000) 67,000    
Unrecognized excess tax benefit $ 3,892,000       $ 3,298,000       3,892,000 $ 3,298,000 $ 2,815,000   $ 1,411,000
ASU 2016-09 [Member]                          
Organization And Basis Of Presentation [Line Items]                          
Income tax benefit                 $ 800,000        
Unrecognized excess tax benefit                       $ 700,000  
Minimum [Member]                          
Organization And Basis Of Presentation [Line Items]                          
Property and equipment, estimated useful lives                 3 years        
Maximum [Member]                          
Organization And Basis Of Presentation [Line Items]                          
Property and equipment, estimated useful lives                 5 years