Goodwill and Intangible Assets, Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 80,144	$ 67,395
Accumulated Amortization	(26,736)	(21,290)
Net Carrying Amount	53,408	46,105
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	68,959	54,389
Accumulated Amortization	(23,397)	(16,595)
Net Carrying Amount	45,562	37,794
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,235	1,601
Accumulated Amortization	(719)	(866)
Net Carrying Amount	516	735
Customer Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	350	2,341
Accumulated Amortization	(88)	(2,265)
Net Carrying Amount	262	76
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	100	167
Accumulated Amortization	(33)	(148)
Net Carrying Amount	67	19
Internally Developed Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9,500	8,897
Accumulated Amortization	(2,499)	(1,416)
Net Carrying Amount	$ 7,001	$ 7,481