Goodwill and Intangible Assets, Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Intangible Assets, Net [Abstract]
Gross carrying amounts	$ 90,686	$ 80,428
Accumulated amortization	(35,404)	(35,313)
Net carrying amounts	55,282	45,115
Customer Relationships [Member]
Intangible Assets, Net [Abstract]
Gross carrying amounts	75,857	67,648
Accumulated amortization	(29,475)	(30,458)
Net carrying amounts	46,382	37,190
Non-Compete Agreements [Member]
Intangible Assets, Net [Abstract]
Gross carrying amounts	1,586	1,018
Accumulated amortization	(628)	(557)
Net carrying amounts	958	461
Customer Backlog [Member]
Intangible Assets, Net [Abstract]
Gross carrying amounts	1,640	390
Accumulated amortization	(451)	(195)
Net carrying amounts	1,189	195
Trade Name [Member]
Intangible Assets, Net [Abstract]
Gross carrying amounts	140	30
Accumulated amortization	(53)	(7)
Net carrying amounts	87	23
Internally Developed Software [Member]
Intangible Assets, Net [Abstract]
Gross carrying amounts	11,463	11,342
Accumulated amortization	(4,797)	(4,096)
Net carrying amounts	$ 6,666	$ 7,246