Other Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 78,665	$ 78,146
Less accumulated amortization	(52,024)	(50,583)
Intangible assets, net	26,641	27,563
Trade names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 2,510	2,510
Acquired finite-lived intangible assets, weighted average useful life	13 years 3 months 18 days
Customer lists [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 75,124	74,615
Acquired finite-lived intangible assets, weighted average useful life	14 years 6 months
Noncompete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 974	964
Acquired finite-lived intangible assets, weighted average useful life	4 years
Patents [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 57	$ 57
Acquired finite-lived intangible assets, weighted average useful life	9 years