Stockholders' Equity - Additional information (Detail) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested share-based compensation awards granted	$ 8,100
Unrecognized compensation cost related to non-vested share-based compensation awards granted year	2020
Stock option exercisable	1,807,765
Number of shares exercised	151,373
Proceeds from exercise of stock options	$ 313	$ 297
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	2,342,315
Fair market value of RSUs granted	$ 4,500
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	3 years
Number of equity instruments awarded in period	2,060,000
Restricted Stock Units (RSUs) [Member] \| Time-Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vesting	50.00%
Restricted Stock Units (RSUs) [Member] \| Performance-Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vesting	50.00%
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	1 year
Number of equity instruments awarded in period	120,000
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Granted	908,661
Fair market value of shares granted	$ 1,800
Term of options granted period	10 years
Vesting period of shares	3 years
Employees [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	540,000
Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of options granted period	10 years
Vesting period of shares	1 year
Vesting period, description	One-half of those Options vest at grant date and the remaining half vest in one year
Directors [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	162,315
Directors [Member] \| Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of shares	1 year
Vesting period, description	One-half of those RSUs vest at grant date and the remaining half vest in one year
Number of equity instruments awarded in period	162,315
Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares exercised	150,000
Proceeds from exercise of stock options	$ 300
Executive Officer [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	1,640,000

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