Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Restricted Stock Activity (Detail)

v3.20.1
Stockholders' Equity - Restricted Stock Activity (Detail) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of shares, Restricted stock granted 290,000 490,000
Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of shares, Unvested balance 12,645,982 11,874,034
Number of shares, Restricted stock granted 1,546,408 1,721,802
Number of shares, Restricted stock vested (220,000) (213,334)
Number of shares, Restricted stock units granted 290,000 490,000
Number of shares, Restricted stock units forfeited   (474,478)
Number of shares Restricted stock units vested (358,960) (752,042)
Sharebased Compensation Arrangement By Sharebased Payment Award Nonoption Equity Instruments Forfeited 135,416  
Number of shares, Unvested balance 13,768,014 12,645,982
Weighted average grant price, Unvested balance $ 2.72 $ 2.63
Weighted average grant price, Restricted stock granted 0.88 3.81
Weighted average grant price, Restricted stock vested 3.16 2.76
Weighted average grant price, Restricted stock units granted 1.49 3.64
Weighted average grant price, Restricted stock units forfeited 3.91 3.94
Weighted average grant price, Restricted stock units vested 3.61 3.56
Weighted average grant price, Unvested balance $ 2.46 $ 2.72