Net Loss Per Share (Calculations for EPS) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Equity [Abstract]
Net loss	$ (5,827)	$ (6,529)	$ (10,411)	$ (13,113)
Basic and diluted weighted average shares outstanding (in shares)	30,978,662	31,330,799	30,978,310	31,380,899
Basic and diluted net loss per share (in dollars per share)	$ (0.19)	$ (0.21)	$ (0.34)	$ (0.42)