XML 12 R33.htm IDEA: XBRL DOCUMENT v3.2.0.727
Stock-Based Awards - Summary of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense $ 1,939 $ 268 $ 2,996 $ 444
Research and Development [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense 738 99 1,142 168
General and Administrative [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense $ 1,201 $ 169 $ 1,854 $ 276