EQUITY - Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Equity [Abstract]
Balance	$ 962,147		$ 610,540	$ 610,540	$ 632,348
Net Income (Loss) Attributable to Redeemable Noncontrolling Interests	12,236	$ 20,876	7,658	19,894	64,196
Capital contributions			349,451	450,330	189,172
Capital distributions			(5,502)	(10,189)	(525)
Balance	$ 1,070,575	$ 570,134	$ 962,147	$ 1,070,575	$ 570,134