Charges Related To Restructuring Activities (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 1,149,000	$ 1,682,000		$ 1,682,000
Charges	1,321,000	692,000	$ 344,000	2,013,000	$ 745,000
Payments	(888,000)	(1,225,000)		(2,113,000)	(3,474,000)
Ending Balance	1,582,000	1,149,000		1,582,000
Severance
Restructuring Reserve [Roll Forward]
Beginning Balance	1,122,000	1,657,000		1,657,000
Charges	1,299,000	670,000
Payments	(839,000)	(1,205,000)
Ending Balance	1,582,000	1,122,000		1,582,000
Contract Termination
Restructuring Reserve [Roll Forward]
Beginning Balance	27,000	25,000		25,000
Charges		22,000
Restructuring Reserve, Accrual Adjustment	22,000
Payments	(49,000)	(20,000)
Ending Balance	0	27,000		0
All Other
Restructuring Reserve [Roll Forward]
Beginning Balance	327,000	820,000		820,000
Charges	346,000	(181,000)	247,000	165,000	258,000
Payments	(64,000)	(312,000)
Ending Balance	609,000	327,000		609,000
All Other | Severance
Restructuring Reserve [Roll Forward]
Beginning Balance	327,000	820,000		820,000
Charges	346,000	(181,000)			258,000
Payments	(64,000)	(312,000)
Ending Balance	609,000	327,000		609,000
All Other | Contract Termination
Restructuring Reserve [Roll Forward]
Beginning Balance	0	0		0
Charges	0	0
Payments	0	0
Ending Balance	0	0		0
Europe
Restructuring Reserve [Roll Forward]
Beginning Balance	276,000	181,000		181,000
Charges	320,000		108,000	640,000	401,000
Payments	(309,000)	(225,000)
Ending Balance	287,000	276,000		287,000
Europe | Severance
Restructuring Reserve [Roll Forward]
Beginning Balance	276,000	181,000		181,000
Charges	320,000	320,000		640,000	401,000
Payments	(309,000)	(225,000)
Ending Balance	287,000	276,000		287,000
Europe | Contract Termination
Restructuring Reserve [Roll Forward]
Beginning Balance	0	0		0
Charges	0	0
Payments	0	0
Ending Balance	0	0		0
North America
Restructuring Reserve [Roll Forward]
Beginning Balance	546,000	681,000		681,000
Charges		553,000	$ (11,000)	1,208,000	86,000
Restructuring Reserve, Accrual Adjustment	655,000
Payments	(515,000)	(688,000)
Ending Balance	686,000	546,000		686,000
North America | Severance
Restructuring Reserve [Roll Forward]
Beginning Balance	519,000	656,000		656,000
Charges	633,000	531,000		1,164,000	221,000
Payments	(466,000)	(668,000)
Ending Balance	686,000	519,000		686,000
North America | Contract Termination
Restructuring Reserve [Roll Forward]
Beginning Balance	27,000	25,000		25,000
Charges				44,000	$ (135,000)
Restructuring Reserve, Accrual Adjustment	22,000	22,000
Payments	(49,000)	(20,000)
Ending Balance	$ 0	$ 27,000		$ 0