STOCK-BASED COMPENSATION - Schedule of expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation before tax	$ 1,517	$ 851	$ 4,240	$ 2,252
Patient care costs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation before tax	171	164	383	348
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation before tax	$ 1,346	$ 687	$ 3,857	$ 1,904