Annual report pursuant to Section 13 and 15(d)

Common Stock - Summary of Stock Options Outstanding Regarding Number of Common Shares Issuable upon Exercise of Outstanding Options (Detail)

v3.3.1.900
Common Stock - Summary of Stock Options Outstanding Regarding Number of Common Shares Issuable upon Exercise of Outstanding Options (Detail)
 12 Months Ended
Dec. 31, 2015
$ / shares
shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Number of Outstanding Options | shares 1,479,221
Exercise Price Range, Weighted Average Exercise Price $ 8.78
Exercise Price Range, Weighted Average Remaining Contractual Life 7 years 6 months 22 days
Range one [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 1.16
Exercise Price Range, Upper Range Limit $ 1.54
Exercise Price Range, Number of Outstanding Options | shares 8,750
Exercise Price Range, Weighted Average Exercise Price $ 1.17
Exercise Price Range, Weighted Average Remaining Contractual Life 9 years 11 months 5 days
Range two [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 1.55
Exercise Price Range, Upper Range Limit $ 1.88
Exercise Price Range, Number of Outstanding Options | shares 424,797
Exercise Price Range, Weighted Average Exercise Price $ 1.86
Exercise Price Range, Weighted Average Remaining Contractual Life 9 years 4 months 17 days
Range three [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 1.89
Exercise Price Range, Upper Range Limit $ 3.04
Exercise Price Range, Number of Outstanding Options | shares 115,500
Exercise Price Range, Weighted Average Exercise Price $ 2.35
Exercise Price Range, Weighted Average Remaining Contractual Life 9 years 2 months 27 days
Range four [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 3.05
Exercise Price Range, Upper Range Limit $ 11.17
Exercise Price Range, Number of Outstanding Options | shares 143,879
Exercise Price Range, Weighted Average Exercise Price $ 5.89
Exercise Price Range, Weighted Average Remaining Contractual Life 7 years 1 month 2 days
Range five [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 11.18
Exercise Price Range, Upper Range Limit $ 11.84
Exercise Price Range, Number of Outstanding Options | shares 218,147
Exercise Price Range, Weighted Average Exercise Price $ 11.78
Exercise Price Range, Weighted Average Remaining Contractual Life 8 years 1 month 21 days
Range six [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 11.85
Exercise Price Range, Upper Range Limit $ 11.99
Exercise Price Range, Number of Outstanding Options | shares 154,251
Exercise Price Range, Weighted Average Exercise Price $ 11.95
Exercise Price Range, Weighted Average Remaining Contractual Life 7 years 1 month 21 days
Range seven [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 12.00
Exercise Price Range, Upper Range Limit $ 13.06
Exercise Price Range, Number of Outstanding Options | shares 136,325
Exercise Price Range, Weighted Average Exercise Price $ 12.87
Exercise Price Range, Weighted Average Remaining Contractual Life 6 years 3 months 4 days
Range eight [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 13.07
Exercise Price Range, Upper Range Limit $ 15.74
Exercise Price Range, Number of Outstanding Options | shares 37,676
Exercise Price Range, Weighted Average Exercise Price $ 14.33
Exercise Price Range, Weighted Average Remaining Contractual Life 5 years 4 months 6 days
Range nine [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 15.75
Exercise Price Range, Upper Range Limit $ 16.40
Exercise Price Range, Number of Outstanding Options | shares 110,250
Exercise Price Range, Weighted Average Exercise Price $ 15.97
Exercise Price Range, Weighted Average Remaining Contractual Life 4 years 11 months 16 days
Range ten [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Exercise Price Range, Lower Range Limit $ 16.41
Exercise Price Range, Upper Range Limit $ 22.28
Exercise Price Range, Number of Outstanding Options | shares 129,646
Exercise Price Range, Weighted Average Exercise Price $ 20.06
Exercise Price Range, Weighted Average Remaining Contractual Life 4 years 2 months 23 days