BUSINESS ACQUISITIONS - Acquired Identifiable Assets and Assumed Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Aug. 06, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 1,428,610	$ 1,428,610	$ 1,427,883	$ 1,425,542	$ 1,419,373		$ 632,469	$ 632,469	$ 632,469
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