Restructuring Charges (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 1,171
Outstanding restructuring liabilities	113
One-time Employee Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	732
Lease Modification Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	326
Losses On Disposal Of Assets [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 113