Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Stock-Based Compensation Expense (Detail)

v3.7.0.1
Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]    
Total stock-based compensation expense $ 2,788 $ 3,194
Research and development [Member]    
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]    
Total stock-based compensation expense 1,218 1,850
General and administrative [Member]    
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]    
Total stock-based compensation expense $ 1,570 $ 1,344