Stockholders' Equity - Additional information (Detail) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested share-based compensation awards granted \| $	$ 4.9
Unrecognized compensation cost related to non-vested share-based compensation awards granted year	2021
Stock option exercisable	1,769,300
Warrant outstanding	2,136,020
Warrant exercise price per share \| $ / shares	$ 2.60
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	1,155,611
Vesting period of shares	3 years
Fair market value of RSUs granted \| $	$ 2.5
Number of restricted shares, Conversions	1,640,198
Restricted Stock Units (RSUs) [Member] \| Time-Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	292,500
Restricted Stock Units (RSUs) [Member] \| Performance-Based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	292,500
Restricted Stock Units (RSUs) [Member] \| Retirement Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted shares, Conversions	570,611
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments awarded in period	618,174
Fair market value of shares granted \| $	$ 1.5
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	317,177

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Exercise price per share or per unit of warrants or rights outstanding.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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