GOODWILL AND INTANGIBLE ASSETS, NET - Intangible assets, net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Intangible Assets, Net
Gross carrying amount	$ 333,787		$ 333,787
Accumulated amortization	(187,501)		(178,355)
Net book value	146,286		155,432
Amortization expense for definite lived intangible assets	9,146	$ 12,211
2017	35,400
2018	26,700
2019	21,200
2020	17,300
2021	12,600
Trademarks and trade names
Intangible Assets, Net
Gross carrying amount	15,354		15,354
Accumulated amortization	(8,026)		(7,724)
Net book value	7,328		7,630
Customer related intangible assets
Intangible Assets, Net
Gross carrying amount	277,828		277,828
Accumulated amortization	(165,094)		(156,980)
Net book value	112,734		120,848
Operating agreement
Intangible Assets, Net
Gross carrying amount	35,000		35,000
Accumulated amortization	(12,542)		(12,104)
Net book value	22,458		22,896
Non-compete agreements
Intangible Assets, Net
Gross carrying amount	1,560		1,560
Accumulated amortization	(604)		(507)
Net book value	956		1,053
Intellectual property
Intangible Assets, Net
Gross carrying amount	300		300
Accumulated amortization	(92)		(85)
Net book value	208		215
Other intangible assets
Intangible Assets, Net
Gross carrying amount	3,745		3,745
Accumulated amortization	(1,143)		(955)
Net book value	$ 2,602		$ 2,790
Weighted Average | Trademarks and trade names
Intangible Assets, Net
Weighted average estimated useful life (in years)	13 years
Weighted Average | Customer related intangible assets
Intangible Assets, Net
Weighted average estimated useful life (in years)	10 years
Weighted Average | Operating agreement
Intangible Assets, Net
Weighted average estimated useful life (in years)	20 years
Weighted Average | Non-compete agreements
Intangible Assets, Net
Weighted average estimated useful life (in years)	4 years
Weighted Average | Intellectual property
Intangible Assets, Net
Weighted average estimated useful life (in years)	10 years
Weighted Average | Other intangible assets
Intangible Assets, Net
Weighted average estimated useful life (in years)	5 years