EMPLOYEE BENEFIT PLANS AND COLLECTIVE BARGAINING AGREEMENTS - Narrative (Details) $ in Millions	4 Months Ended	12 Months Ended
	Jun. 18, 2016 USD ($)	Feb. 23, 2019 USD ($) employee	Feb. 24, 2018 USD ($) employee	Feb. 25, 2017 USD ($)	Feb. 22, 2020 employee	May 15, 2016	Jan. 30, 2015 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		$ 199.3	$ 21.9
Current fiscal year contributions		150.0
Expected employer contribution next fiscal year		$ 12.4
Entity number of employees | employee		267,000
Number of participants in collective bargaining agreements | employee		170,000	8,500
Multiemployer plan contributions		$ 1,300.0	$ 1,200.0	$ 1,200.0
Employer discretionary contribution amount in 401(k)		45.1	44.6	38.8
UFCW Midwest Plan
Defined Benefit Plan Disclosure [Line Items]
Withdrawal obligation recorded		142.1					$ 221.8
Forecast
Defined Benefit Plan Disclosure [Line Items]
Number of employee scheduled to expire in collective bargaining agreements | employee					106,000
Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0	0.0	0.0
Employer contributions		2.1	1.7
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,847.0	1,814.0	$ 1,934.8
Payable to intermediary agent		79.5	87.4
Employer contributions		197.2	$ 20.2
Pension | Safeway Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,600.0
Pension | Shaw's Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		247.0
Pension | United Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 33.0
Collington
Defined Benefit Plan Disclosure [Line Items]
Percentage of equity interest acquired						100.00%
Pension expense from acquisition	$ 78.9
Collington | Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service costs recorded relate to Collington transaction	$ 15.5