GOODWILL AND OTHER INTANGIBLE ASSETS, Amortizable Other Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 163,150	$ 164,858
Accumulated amortization	(80,105)	(70,027)
Carrying amount, net	83,045	94,831
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	162,201	163,022
Accumulated amortization	(79,315)	(68,446)
Carrying amount, net	82,886	94,576
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	949	1,836
Accumulated amortization	(790)	(1,581)
Carrying amount, net	$ 159	$ 255