Loss Per Common Share (Computation Of Basic And Diluted (Loss) Income Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Basic loss per common share
Net loss	$ (2,178)	$ (3,689)	$ (5,316)	$ (10,354)
Net loss allocated to participating securities	14	24	36	73
Net loss allocated to common shareholders	$ (2,164)	$ (3,665)	$ (5,280)	$ (10,281)
Basic weighted-average common shares outstanding	38,943	37,520	38,841	37,455
Basic loss per common share	$ (0.06)	$ (0.10)	$ (0.14)	$ (0.27)
Diluted loss per common share
Net loss	$ (2,178)	$ (3,689)	$ (5,316)	$ (10,354)
Net loss allocated to participating securities	14	24	36	73
Net loss allocated to common shareholders	$ (2,164)	$ (3,665)	$ (5,280)	$ (10,281)
Basic weighted-average common shares outstanding	38,943	37,520	38,841	37,455
Diluted weighted-average common shares outstanding	38,943	37,520	38,841	37,455
Diluted loss per common share	$ (0.06)	$ (0.10)	$ (0.14)	$ (0.27)