Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Restricted Stock (Details)

v3.20.1
Stockholders' Equity - Restricted Stock (Details) - Unvested restricted stock (Note 6) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of Shares, Nonvested Beginning Balance 2,932,106 2,611,116
Number of Shares, Granted 800,652 616,240
Number of Shares, Forfeited (21,000)  
Number of Shares, Vested (407,919) (295,250)
Number of Shares, Nonvested Ending Balance 3,303,839 2,932,106
Weighted Average Exercise Price, Nonvested Beginning Balance $ 4.22 $ 3.89
Weighted Average Grant Date Fair Value, Granted 3.33 3.75
Weighted Average Grant Date Fair Value, Forfeited 3.16  
Weighted Average Grant Date Fair Value, Vested 1.96 0.29
Weighted Average Exercise Price, Nonvested Ending Balance $ 4.29 $ 4.22