Stockholders' Equity - Shares of Common Stock Issuable on Conversion or Exercise of Rights Granted (Detail)	Dec. 31, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total common shares	25,240,381
Exercise of Issued Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total common shares	445,000
2018 Convertible Notes [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total common shares	10,454,799
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total common shares	14,340,582
Management Incentive Plan Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total common shares	0