XML 91 R73.htm IDEA: XBRL DOCUMENT v3.8.0.1
Share-based Compensation - Summary of Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Stock Options Outstanding    
Outstanding — beginning of period 6,356,203 6,084,836
Granted 3,877,000 1,051,550
Exercised (146,039) (78,384)
Canceled (3,520,681) (701,799)
Outstanding — end of period 6,566,483 6,356,203
Vested and Expected to Vest — December 31, 2017 5,815,396  
Exercisable — December 31, 2017 2,202,598  
Weighted-Average Exercise Price Per Option    
Outstanding — beginning of period $ 2.64 $ 3.01
Granted 1.15 1.65
Exercised 1.11 1.12
Canceled 2.69 4.35
Outstanding — end of period 1.77 $ 2.64
Vested and Expected to Vest — December 31, 2017 1.84  
Exercisable — December 31, 2017 $ 2.83  
Weighted-Average Remaining Contractual Term (Years), Options Outstanding 8 years 2 months 5 days  
Weighted-Average Remaining Contractual Term (Years), Options Vested and Expected to Vest 8 years 12 days  
Weighted-Average Remaining Contractual Term (Years), Options Exercisable 6 years 1 month 12 days  
Aggregate Intrinsic Value, Options Outstanding $ 2,460  
Aggregate Intrinsic Value, Options Vested and Expected to Vest 2,132  
Aggregate Intrinsic Value, Options Exercisable $ 491