Quarterly report pursuant to Section 13 or 15(d)

Stock Based Compensation - Stock Option Activity Under Equity Incentive Plan (Detail)

v3.7.0.1
Stock Based Compensation - Stock Option Activity Under Equity Incentive Plan (Detail)
6 Months Ended
Jun. 30, 2017
USD ($)
$ / shares
shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]  
Number of Shares, Outstanding, Beginning Balance | shares 10,941,745
Number of Shares, Granted | shares 0
Number of Shares, Exercised | shares 0
Number of Shares, Forfeitures | shares (209,485)
Number of Shares, Outstanding, Ending Balance | shares 10,732,260
Number of Shares, Vested and expected to vest | shares 10,689,426
Number of Shares, Exercisable | shares 8,640,234
Weighted-Average Exercise Price, Outstanding, Beginning Balance | $ / shares $ 3.00
Weighted-Average Exercise Price, Granted | $ / shares 0
Weighted-Average Exercise Price, Exercised | $ / shares 0
Weighted-Average Exercise Price, Forfeitures | $ / shares 1.37
Weighted-Average Exercise Price, Outstanding, Ending Balance | $ / shares 3.03
Weighted-Average Exercise Price, Vested and expected to vest | $ / shares 3.04
Weighted-Average Exercise Price, Exercisable | $ / shares $ 3.38
Weighted-Average Remaining Contractual Term, Outstanding 4 years 10 months 28 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest 4 years 10 months 21 days
Weighted-Average Remaining Contractual Term, Exercisable 4 years 26 days
Aggregate Intrinsic Value, Outstanding | $ $ 2,730
Aggregate Intrinsic Value, Vested and expected to vest | $ 2,730
Aggregate Intrinsic Value, Exercisable | $ $ 2,730