GOODWILL AND INTANGIBLES ASSETS, NET - Changes in the Carrying Amount of Goodwill by Reportable Segment (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Goodwill [Roll Forward]
Balance at beginning of period	$ 142,113
Foreign currency translation adjustment	(13,536)
Goodwill acquired	194,508
Balance at end of period	323,085
Office Segment
Goodwill [Roll Forward]
Balance at beginning of period	36,220
Foreign currency translation adjustment	(210)
Goodwill acquired	0
Balance at end of period	36,010
Lifestyle Segment
Goodwill [Roll Forward]
Balance at beginning of period	105,893
Foreign currency translation adjustment	(13,326)
Goodwill acquired	194,508
Balance at end of period	$ 287,075