Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basic and Diluted
Net loss attributable to American Renal Associates Holdings, Inc.	$ 90	$ 4,777	$ (8,178)	$ (10,479)	$ (572)	$ (734)	$ (23,659)	$ (3,802)	$ (13,790)	$ (28,767)	$ (4,597)
Change in the difference between the redemption values and estimated fair values for accounting purposes of the related noncontrolling interests									(7,999)	(2,566)	(11,503)
Net income (loss) attributable to common shareholders									$ (21,789)	$ (31,333)	$ (16,100)
Weighted-average common shares outstanding (in shares)									32,274,570	31,965,844	31,081,824
Weighted-average common shares outstanding, assuming dilution (in shares)									32,274,570	31,965,844	31,081,824
Loss per share, basic and diluted (in USD per share)									$ (0.68)	$ (0.98)	$ (0.52)
Outstanding options excluded as impact would be antidilutive (in shares)									2,986,656	3,442,048	1,894,340