Net Earnings (Loss) Per Common Share - Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income (loss)	$ 3,470	$ (19,792)	$ (2,844)	$ (1,069)	$ (4,651)	$ (7,659)	$ (19,166)	$ (13,379)
Denominator:
Weighted Average Number of Shares Outstanding, Basic (in shares)	44,251			42,925			43,979	39,163
Weighted Average Number of Shares Outstanding, Diluted (in shares)	46,667			42,925			43,979	39,163
Earnings Per Share, Basic (in dollars per share)	$ 0.08			$ (0.02)			$ (0.44)	$ (0.34)
Earnings Per Share, Diluted (in dollars per share)	$ 0.07			$ (0.02)			$ (0.44)	$ (0.34)
Options
Denominator:
Aggregate number of common equivalent shares (related to options, warrants and preferred stock) excluded from diluted net loss per common share (in shares)	1,619			5,196			5,116	5,196
Restricted Stock
Denominator:
Aggregate number of common equivalent shares (related to options, warrants and preferred stock) excluded from diluted net loss per common share (in shares)							159
Warrants Amounts
Denominator:
Aggregate number of common equivalent shares (related to options, warrants and preferred stock) excluded from diluted net loss per common share (in shares)				112				112