ACQUISITIONS - Schedule of Finite-Lived Intangible Assets Acquired (Details) - Supervalu $ in Thousands	Nov. 02, 2019 USD ($)
Non-compete agreement
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Minimum | Customer relationship assets
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years
Minimum | Favorable operating leases
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Minimum | Leases in place
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Minimum | Tradenames
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Minimum | Pharmacy prescription files
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Minimum | Unfavorable operating leases
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Maximum | Customer relationship assets
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years
Maximum | Favorable operating leases
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	19 years
Maximum | Leases in place
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years
Maximum | Tradenames
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	9 years
Maximum | Pharmacy prescription files
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Maximum | Unfavorable operating leases
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years
Continuing Operations
Business Acquisition [Line Items]
Finite Lived Intangible Assets	$ 896,349
Continuing Operations | Customer relationship assets
Business Acquisition [Line Items]
Finite Lived Intangible Assets	810,000
Continuing Operations | Favorable operating leases
Business Acquisition [Line Items]
Finite Lived Intangible Assets	21,629
Continuing Operations | Leases in place
Business Acquisition [Line Items]
Finite Lived Intangible Assets	10,474
Continuing Operations | Tradenames
Business Acquisition [Line Items]
Finite Lived Intangible Assets	66,000
Continuing Operations | Pharmacy prescription files
Business Acquisition [Line Items]
Finite Lived Intangible Assets	0
Continuing Operations | Non-compete agreement
Business Acquisition [Line Items]
Finite Lived Intangible Assets	10,000
Continuing Operations | Unfavorable operating leases
Business Acquisition [Line Items]
Finite Lived Intangible Assets	21,754
Discontinued Operations
Business Acquisition [Line Items]
Finite Lived Intangible Assets	62,900
Discontinued Operations | Customer relationship assets
Business Acquisition [Line Items]
Finite Lived Intangible Assets	0
Discontinued Operations | Favorable operating leases
Business Acquisition [Line Items]
Finite Lived Intangible Assets	0
Discontinued Operations | Leases in place
Business Acquisition [Line Items]
Finite Lived Intangible Assets	0
Discontinued Operations | Tradenames
Business Acquisition [Line Items]
Finite Lived Intangible Assets	17,000
Discontinued Operations | Pharmacy prescription files
Business Acquisition [Line Items]
Finite Lived Intangible Assets	45,900
Discontinued Operations | Non-compete agreement
Business Acquisition [Line Items]
Finite Lived Intangible Assets	0
Discontinued Operations | Unfavorable operating leases
Business Acquisition [Line Items]
Finite Lived Intangible Assets	$ 0