BUSINESS ACQUISITIONS - Acquired Identifiable Assets and Assumed Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Aug. 06, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 1,428,610	$ 1,425,542		$ 632,469	$ 627,392
BioScrip
Business Acquisition [Line Items]
Accounts receivable, net			$ 96,532
Inventories			19,683
Property and equipment, net			48,732
Intangible assets, net			193,245
Deferred tax assets, net of deferred tax liabilities			26,731
Operating lease right-of-use asset			22,378
Operating lease liability			(28,897)
Accounts payable			(66,668)
Other assumed liabilities, net of other acquired assets			(20,663)
Total acquired identifiable assets and liabilities			291,073
Goodwill			796,141
Total consideration transferred			$ 1,087,214