Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies - Summary of Potentially Dilutive Adjustments to Weighted Average Number of Common Shares Excluded from Calculation (Detail)

v3.21.1
Significant Accounting Policies - Summary of Potentially Dilutive Adjustments to Weighted Average Number of Common Shares Excluded from Calculation (Detail) - shares
shares in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share (shares) 262 343
Common stock purchase warrants    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share (shares) 206 279
Stock options    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share (shares) 56 64