CHANGES IN OWNERSHIP INTEREST IN CONSOLIDATED SUBSIDIARIES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Noncontrolling Interest [Abstract]
Net income (loss) attributable to American Renal Associates Holdings, Inc.	$ 795	$ (8,178)	$ (6,439)	$ (18,657)
Increase in paid-in capital for the sales of noncontrolling interest	0	0	3,448	0
Decrease in paid-in capital for the purchase of noncontrolling interest and adjustments to ownership interest	(886)	(7,590)	(886)	(7,540)
Net transfers to/from noncontrolling interests	(886)	(7,590)	2,562	(7,540)
Net loss attributable to American Renal Holdings Associates, Inc., net of transfers to/from noncontrolling interests	$ (91)	$ (15,768)	$ (3,877)	$ (26,197)