Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets, Net [Abstract]
Amortized intangible assets, Gross Carrying Value	$ 94,526	$ 93,641
Accumulated Amortization	(34,191)	(31,320)
Amortized intangible assets, Net Carrying Value	60,335	62,321
Intangible Assets, Gross (Excluding Goodwill)	94,986	94,101
Other intangible assets, net	60,795	62,781
Customer contracts and relationships
Finite-Lived Intangible Assets, Net [Abstract]
Amortized intangible assets, Gross Carrying Value	69,074	68,798
Accumulated Amortization	(25,930)	(23,696)
Amortized intangible assets, Net Carrying Value	43,144	45,102
Operating contracts and licenses
Finite-Lived Intangible Assets, Net [Abstract]
Amortized intangible assets, Gross Carrying Value	9,702	9,951
Accumulated Amortization	(1,086)	(1,094)
Amortized intangible assets, Net Carrying Value	8,616	8,857
Tradenames
Finite-Lived Intangible Assets, Net [Abstract]
Amortized intangible assets, Gross Carrying Value	8,656	8,633
Accumulated Amortization	(3,137)	(2,873)
Amortized intangible assets, Net Carrying Value	5,519	5,760
Other
Finite-Lived Intangible Assets, Net [Abstract]
Amortized intangible assets, Gross Carrying Value	1,699	896
Accumulated Amortization	(682)	(650)
Amortized intangible assets, Net Carrying Value	1,017	246
Non-compete agreements
Finite-Lived Intangible Assets, Net [Abstract]
Amortized intangible assets, Gross Carrying Value	5,395	5,363
Accumulated Amortization	(3,356)	(3,007)
Amortized intangible assets, Net Carrying Value	2,039	2,356
Business licenses
Finite-Lived Intangible Assets, Net [Abstract]
Unamortized intangible assets, Gross Carrying Value	$ 460	$ 460