CERTAIN LEGAL AND OTHER MATTERS (Details) $ in Thousands					12 Months Ended
	Jul. 02, 2020 USD ($)	Mar. 11, 2020 USD ($)	Aug. 01, 2019 USD ($)	Aug. 01, 2018 USD ($)	Dec. 31, 2018 USD ($) paymentInstallment	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Loss Contingencies [Line Items]
Accrued expenses and other current liabilities						$ 173,614	$ 37,593
Other long-term liabilities						10,876	$ 6,501
ARA, ARA OpCo And ARM vs UnitedHealth Group Inc.
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party				$ 32,000
Number of installments | paymentInstallment					5
Estimated litigation liability					$ 29,614	12,715
Accrued expenses and other current liabilities						6,939
Other long-term liabilities						5,776
Settlement payment			$ 8,000	$ 10,000
Installment payment to be paid August 1, 2020						7,000
Installment payment to be paid August 1, 2021						3,500
Installment payment to be paid August 1, 2022						$ 3,500
Agreement term				3 years
Pending Litigation | Ali Vandevar, et al. v. American Renal Associates Holdings Inc., et al.
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party		$ 5,775
Settled Litigation | Luke Johnson v. Joseph A. Carlucci, et al. | Subsequent Event
Loss Contingencies [Line Items]
Litigation settlement, amount awarded from other party	$ 413