GOODWILL AND INTANGIBLE ASSETS - NET (Intangible Assets Compinents and Amortization Expenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 71,787	$ 59,573
Accumulated amortization	(20,527)	(12,713)
Net carrying amount	51,260	46,860
Amortization of Intangible Assets	$ 8,170	$ 5,416	$ 5,349
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted average life at acquisition (in years)	10 years	10 years
Gross carrying amount	$ 65,409	$ 52,974
Accumulated amortization	(15,133)	(8,387)
Net carrying amount	50,276	44,587
Amortization of Intangible Assets	$ 6,858	$ 3,961	3,843
Trade names
Finite-Lived Intangible Assets [Line Items]
Weighted average life at acquisition (in years)	5 years	5 years
Gross carrying amount	$ 5,622	$ 5,853
Accumulated amortization	(4,661)	(3,772)
Net carrying amount	961	2,081
Amortization of Intangible Assets	$ 1,139	$ 1,280	1,319
Non-competition agreements
Finite-Lived Intangible Assets [Line Items]
Weighted average life at acquisition (in years)	4 years	4 years
Gross carrying amount	$ 756	$ 746
Accumulated amortization	(733)	(554)
Net carrying amount	23	192
Amortization of Intangible Assets	$ 173	$ 175	$ 187