SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Intangible Assets, Segment Reporting, Insurance Reserves and Capitalized Interest (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) item	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Segment Reporting
Number of Reportable Segments | item	1
Self-insurance Reserves
Period for reviewing actual expenditure to determine self-insurance reserve	12 months
Debt Issuance Costs
Loan issuance costs, net of amortization	$ 2,400
Capitalized Interest
Interest Costs Capitalized	548	$ 381	$ 152
Customer Relationships [Member]
Finite-lived intangible assets
Net intangible asset	$ 5,000	$ 6,200