XML 67 R52.htm IDEA: XBRL DOCUMENT v3.8.0.1
Share/Stock-Based Compensation - Summary of Employee and Non-Employee Restricted Stock Activity (Details) - Unvested Restricted Common Stock
12 Months Ended
Dec. 31, 2017
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Shares, Unvested restricted common stock, Beginning balance | shares 75,932
Shares, Vested | shares (42,206)
Shares, Forfeited | shares (419)
Shares, Unvested restricted common stock, Ending balance | shares 33,307
Weighted Average Grant Date Fair Value, Unvested restricted common stock, Beginning balance | $ / shares $ 1.96
Weighted Average Grant Date Fair Value, Vested | $ / shares 1.86
Weighted Average Grant Date Fair Value, Forfeited | $ / shares 1.72
Weighted Average Grant Date Fair Value, Unvested restricted common stock, Ending balance | $ / shares $ 1.84