XML 58 R46.htm IDEA: XBRL DOCUMENT v3.19.1
Net Loss Per Share (Details Textual) - shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Earnings Per Share [Abstract]    
Shares issuable excluded from computation of diluted net loss per share and unvested shares 1,037,797 980,588