Quarterly report pursuant to Section 13 or 15(d)

Net Loss per Share (Details)

Net Loss per Share (Details) - shares
shares in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2018
Earnings Per Share [Abstract]    
Weighted average shares excluded from the calculation of diluted weighted average shares outstanding (in shares) 3.6 14.7