BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Details)					1 Months Ended	6 Months Ended	12 Months Ended
	Apr. 11, 2019 USD ($) State Location	Aug. 31, 2018 USD ($) Installment Clinic	Apr. 30, 2018 USD ($) Business	Feb. 28, 2018 Clinic	Mar. 31, 2017 USD ($)	Jun. 30, 2019 USD ($) State Clinic Facility Region	Dec. 31, 2018 USD ($) Clinic
Basis of Presentation [Abstract]
Seller notes			$ 950,000
Percentage of general partnership interest owned						1.00%
Number of clinic practices acquired | Clinic		4		2			5
Number of clinics operated | Clinic						564
Number of states where clinics are operated | State						41
Number of third party facilities | Facility						26
Goodwill [Abstract]
Number of regions | Region						6
Income Taxes [Abstract]
Unrecognized tax benefit						$ 0
Accrued interest and penalties associated with any unrecognized tax benefits						0
Interest expense recognized						0
Recently Adopted Accounting Guidance [Abstract]
Operating lease right-of-use assets						74,930,000	$ 0
Lease Liability						79,269,000
ASU 2016-02 [Member]
Recently Adopted Accounting Guidance [Abstract]
Operating lease right-of-use assets						78,000,000
Lease Liability						$ 82,600,000
April 2019 Acquisition [Member]
Basis of Presentation [Abstract]
Acquisition date						Apr. 11, 2019
Number of states of network services | State	45
Number of onsite client locations | Location	11
Percentage of interest acquired	76.00%
Aggregate purchase price for the acquired clinic practices	$ 23,600,000
Cash paid for acquisition of interest in clinic	19,600,000
Payable to shareholders of seller	500,000
Seller notes	$ 4,000,000
Percentage of interest accrued	5.50%
August 2018 Acquisition [Member]
Basis of Presentation [Abstract]
Acquisition date						Aug. 31, 2018
Percentage of interest acquired		70.00%
Cash paid for acquisition of interest in clinic		$ 7,200,000
Seller notes		$ 400,000
Business acquisition number of installments to payment of purchase consideration | Installment		2
Number of clinic practices acquired | Clinic		4
August 2018 Acquisition [Member] | August 2019 [Member]
Basis of Presentation [Abstract]
Acquisition cost payable in two principal installments including accrued interest		$ 200,000
August 2018 Acquisition [Member] | August 2020 [Member]
Basis of Presentation [Abstract]
Acquisition cost payable in two principal installments including accrued interest		$ 200,000
March 2017 Acquisition [Member]
Basis of Presentation [Abstract]
Percentage of interest acquired					55.00%
Industrial Injury Prevention [Member]
Basis of Presentation [Abstract]
Percentage of interest acquired			65.00%		55.00%
Cash paid for acquisition of interest in clinic			$ 8,600,000		$ 6,200,000
Seller notes			$ 400,000		$ 400,000
Number of businesses merged | Business			2
Percentage of combined business interest owned			59.45%
Employee [Member]
Restricted Stock [Abstract]
Period in which restrictions lapse on stock granted						4 years
Director [Member]
Restricted Stock [Abstract]
Period in which restrictions lapse on stock granted						1 year
Officer [Member]
Restricted Stock [Abstract]
Period in which restrictions lapse on stock granted						4 years
Minimum [Member]
Basis of Presentation [Abstract]
Percentage of limited partnership interest owned						49.00%
Redeemable Non-Controlling Interests [Abstract]
Redeemable non-controlling interest, redemption rights, commencement period						3 years
Minimum [Member] | Furniture & Equipment [Member]
Long-Lived Assets [Abstract]
Estimated useful lives						3 years
Minimum [Member] | Software [Member]
Long-Lived Assets [Abstract]
Estimated useful lives						3 years
Minimum [Member] | Leasehold Improvements [Member]
Long-Lived Assets [Abstract]
Estimated useful lives						3 years
Maximum [Member]
Basis of Presentation [Abstract]
Percentage of limited partnership interest owned						99.00%
Redeemable Non-Controlling Interests [Abstract]
Redeemable non-controlling interest, redemption rights, commencement period						5 years
Maximum [Member] | Furniture & Equipment [Member]
Long-Lived Assets [Abstract]
Estimated useful lives						8 years
Maximum [Member] | Software [Member]
Long-Lived Assets [Abstract]
Estimated useful lives						7 years
Maximum [Member] | Leasehold Improvements [Member]
Long-Lived Assets [Abstract]
Estimated useful lives						5 years