REDEEMABLE NON-CONTROLLING INTEREST (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) Partnership	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Business Combination, Description [Abstract]
Sale of non-controlling interest percentage in partnership			50.00%
Number of partnerships in which interest acquired | Partnership			3
Purchase price for additional non controlling interest			$ 2,200	$ 0
Excess of purchase price of non controlling interest			400
Excess of purchase of non controlling interest, net of tax			$ 100
Number of partnerships in which various interest sold | Partnership			3
Sale price of non controlling interest in partnership			$ 2,780	0
Changes in Carrying Amount of Redeemable Non-Controlling Interests [Roll Forward]
Beginning balance			133,943
Ending balance	$ 133,366		133,366
Carrying Amount (Fair Value) of Redeemable Non-Controlling Interest [Abstract]
Fair value	133,366		133,366		$ 133,366
Redeemable Non-Controlling Interest [Member]
Changes in Carrying Amount of Redeemable Non-Controlling Interests [Roll Forward]
Beginning balance	137,196	$ 108,085	133,943	102,572
Operating results allocated to redeemable non-controlling interest partners	3,378	2,610	5,773	4,346
Distributions to redeemable non-controlling interest partners	(3,641)	(2,720)	(5,163)	(4,079)
Changes in the fair value of redeemable non-controlling interest	5,169	4,344	9,830	9,425
Purchases of redeemable non-controlling interest	(2,604)	4,863	(4,885)	4,863
Reduction of non-controlling interest due to sale of USPh partnership interest	(6,132)	0	(6,132)	0
Sales of redeemable non-controlling interest - temporary equity	2,870	0	2,870	0
Notes receivable related to sales of redeemable non-controlling interest - temporary equity	(2,870)	0	(2,870)	0
Other	0	(155)	0	(100)
Ending balance	133,366	117,027	133,366	117,027
Carrying Amount (Fair Value) of Redeemable Non-Controlling Interest [Abstract]
Contractual time period has lapsed but holder's employment has not been terminated					52,937	$ 34,144
Contractual time period has not lapsed and holder's employment has not been terminated					80,429	82,883
Holder's employment has terminated and contractual time period has expired					0	0
Holder's employment has terminated and contractual time period has not expired					0	0
Fair value	$ 137,196	$ 108,085	$ 133,943	$ 102,572	$ 133,366	$ 117,027
Therapy Practice [Member] | Minimum [Member]
Business Combination, Description [Abstract]
Business acquisition, percentage of limited partnership acquired					50.00%
Therapy Practice [Member] | Maximum [Member]
Business Combination, Description [Abstract]
Business acquisition, percentage of limited partnership acquired					90.00%
Therapy Practice [Member] | NewCo. [Member]
Business Combination, Description [Abstract]
Percentage of equity interest of subsidiary contributed for acquisition					100.00%
Business acquisition, percentage of general partnership interest acquired					100.00%
Business acquisition, consideration payable, term of note			2 years
Employment agreement renewal term			1 year
Non-Compete agreement term under condition of termination of employment of employed selling shareholder			2 years
Therapy Practice [Member] | NewCo. [Member] | Minimum [Member]
Business Combination, Description [Abstract]
Employment agreement term			3 years
Non-Compete agreement term regardless of whether the selling shareholder is employed			5 years
Therapy Practice [Member] | NewCo. [Member] | Maximum [Member]
Business Combination, Description [Abstract]
Employment agreement term			5 years
Non-Compete agreement term regardless of whether the selling shareholder is employed			6 years