BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Millions		4 Months Ended		12 Months Ended
	Apr. 25, 2019 USD ($)	Jun. 15, 2019 USD ($) division store_format segment shares	Jun. 16, 2018 USD ($)	Feb. 23, 2019 USD ($) shares	Feb. 24, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash		$ 51.6		$ 41.6
LIFO expense (benefit)		10.5	$ 9.5
Equity-based compensation expense		1.2
Compensation cost not yet recognized		$ 9.6
Period for recognition of unrecognized compensation cost		4 years 1 month 6 days
Fair value of equity interests deemed granted	$ 10.8
Payments for repurchased of common stock				25.8
Income tax expense (benefit)		$ 15.7	$ (3.0)
Effective tax rate		24.30%	14.50%
Number of divisions | division		13
Number of reportable segments | segment		1
Number of store format | store_format		1
Receivables, net		$ 497.4		586.2
Contract liability related to gift cards		51.7		55.9
Adoption of new accounting standards, net of tax					$ 574.6
Right-of-use assets		5,280.8
Lease liabilities		5,421.2
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of new accounting standards, net of tax					558.0
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment					(776.0)
Adoption of new accounting standards, net of tax					574.6
Right-of-use assets					5,300.0
Lease liabilities					5,400.0
ASU 2016-02, Deferred Gains On Sale-Leaseback
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment					(865.8)
ASU 2016-02, Impairment Loss
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment					87.3
ASU 2016-02, Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment					17.2
ASU 2016-02, Liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment					14.7
ASU 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of new accounting standards, net of tax					$ 16.6
Pharmacy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net		233.8		$ 252.2
Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of shares repurchased (in shares) | shares				1,772,018
Phantom units
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity-based compensation expense		9.9	$ 13.4
Income tax benefit		2.6	$ 3.6
Compensation cost not yet recognized		$ 46.4
Number of unvested phantom units (in shares) | shares		1,700,000
Period for recognition of unrecognized compensation cost		2 years
Phantom units | Investor Incentive Units
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Units received upon vesting (in shares) | shares		1