Net Loss Per Share (Details) - Anti-dilutive common shares - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Anti-dilutive Securities Excluded from Computation of Earnings Per Share, Amount	7,573	4,992	2,581	5,014
Convertible Debt Securities
Anti-dilutive Securities Excluded from Computation of Earnings Per Share, Amount	330	0	332
Employee Stock Option
Anti-dilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,282	3,531	1,027	3,396
Warrant
Anti-dilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,961	1,461	1,222	1,618