Intangible Assets (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	$ 61,883,000	$ 59,380,000
Cost of additions reduced by recognition of tax credits	1,606,000	888,000	$ 1,094,000
Impairment loss		8,911,000	28,243,000
Capitalized cost of software under development	$ 460,000	$ 281,000	$ 356,000
Interest costs, weighted average rate	4.09%	3.18%	4.91%
Weighted average amortization period	8 years 2 months 12 days	7 years 10 months 24 days	8 years 2 months 12 days
Customer Relationships [Member] | EquipmentOne [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment loss		$ 8,911,000	$ 4,669,000