Net Loss per Share - Schedule of Antidilutive Securities Excluded from Calculation of Net Loss per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of net loss per share (in shares)	33,803,260	12,525,879	33,803,260	12,525,879
Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of net loss per share (in shares)	19,667,765	0	19,667,765	0
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of net loss per share (in shares)	11,730,954	11,359,531	11,730,954	11,359,531
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of net loss per share (in shares)	2,271,277	1,033,084	2,271,277	1,033,084
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of net loss per share (in shares)	133,264	133,264	133,264	133,264