PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 209,115		$ 209,115		$ 151,189
Less accumulated depreciation	77,133		77,133		58,047
Property and equipment, net	131,982		131,982		93,142
Depreciation expense	9,906	$ 5,427	21,704	$ 15,787
Infusion pumps
Property, Plant and Equipment [Line Items]
Property and equipment, gross	24,786		24,786		20,339
Equipment, furniture, and other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	60,569		60,569		34,433
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	84,675		84,675		61,302
Computer software, purchased and internally developed
Property, Plant and Equipment [Line Items]
Property and equipment, gross	34,500		34,500		29,668
Assets under development
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,585		4,585		$ 5,447
Depreciation expense in cost of revenue
Property, Plant and Equipment [Line Items]
Depreciation expense	1,384	747	2,855	2,265
Depreciation expense in operating expenses
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 8,522	$ 4,680	$ 18,849	$ 13,522