GOODWILL AND OTHER INTANGIBLE ASSETS, Changes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Goodwill [Roll Forward]
Balance at beginning of period	$ 187,591
Acquired during the period	6,483
Translation adjustment	0
Balance at end of period	194,074
Other Intangibles Assets [Roll Forward]
Balance at beginning of period	78,525
Acquired during the period	6,185
Translation adjustment	(315)
Amortization	(4,358)	$ (4,316)
Balance at end of period	80,037
Total Goodwill and Intangible Assets [Roll Forward]
Balance at beginning of period	266,116
Acquired during the period	12,668
Translation adjustment	(315)
Amortization	(4,358)	$ (4,316)
Balance at end of period	$ 274,111