Revenues (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues	$ 232,913,000	$ 235,774,000	$ 235,858,000	$ 223,419,000	$ 244,576,000	$ 244,559,000	$ 246,152,000	$ 237,060,000	$ 927,964,000	$ 972,347,000	$ 966,497,000
Net Revenue									100.00%	100.00%
Deferred Revenue	$ 3,173,000				$ 2,416,000				$ 3,173,000	$ 2,416,000
Europe
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									533,048,000	558,518,000	535,326,000
North America
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									348,201,000	364,590,000	380,290,000
Other Segments
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									46,715,000	49,239,000	$ 50,881,000
Product [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									$ 907,654,000	$ 951,341,000
Net Revenue									98.00%	98.00%
Product [Member] | Europe
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									$ 519,160,000	$ 544,517,000
Product [Member] | North America
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									346,642,000	362,431,000
Product [Member] | Other Segments
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									41,852,000	44,393,000
Service [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									$ 20,310,000	$ 21,006,000
Net Revenue									2.00%	2.00%
Service [Member] | Europe
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									$ 13,888,000	$ 14,001,000
Service [Member] | North America
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									1,559,000	2,159,000
Service [Member] | Other Segments
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues									$ 4,863,000	$ 4,846,000
General Terms and Conditions [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Contract Type Sales Split									31.00%
Large National Customers [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Contract Type Sales Split									26.00%
Government Tenders [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Contract Type Sales Split									20.00%
Other Customers [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Contract Type Sales Split									23.00%