EMPLOYEE BENEFIT PLANS AND COLLECTIVE BARGAINING AGREEMENTS - Narrative (Details) $ in Millions					3 Months Ended			12 Months Ended
	Dec. 20, 2021 union	Dec. 31, 2020 USD ($)	Jul. 01, 2020 USD ($) union	Jan. 30, 2015 USD ($)	Feb. 26, 2022 USD ($) employee plan	Feb. 27, 2021 USD ($) installment	Dec. 05, 2020 USD ($)	Feb. 26, 2022 USD ($) employee plan	Feb. 27, 2021 USD ($) installment	Feb. 29, 2020 USD ($)	Apr. 26, 2022 employee
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, transferred								$ 203.5
Defined benefit pension obligation								205.4
Defined benefit plan gain (loss) due to settlement								11.1
Employer contributions								29.8	$ 60.0	$ 11.0
Expected employer contribution next fiscal year					$ 21.0			$ 21.0
Number of multiemployer plans | plan					27			27
Number of unions | union			9
Employer discretionary contribution amount in 401(k)								$ 75.5	85.8	63.2
Non-cash pre-tax charge						$ 607.2
Non-cash charge, net of tax						$ 449.4
Amount paid									$ 147.3
Number of installments | installment						2			2
Installment amount									$ 69.2
Number of company employees | employee					290,000			290,000
Number of participants in collective bargaining agreements | employee					200,000			200,000
Number of participants renegotiated | employee					60,000			60,000
Number of employee scheduled to expire in collective bargaining agreements | employee					115,000			115,000
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Number of participants in collective bargaining agreements | employee											74,000
Safeway Inc
Defined Benefit Plan Disclosure [Line Items]
Multiemployer pension withdrawal liability				$ 221.8
Lump sum paid for settlement					$ 75.0
Gain recorded to reduce previously recorded estimated withdrawal liability to settlement amount						$ 43.3
Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan gain (loss) due to settlement								$ 16.2	0.7	(7.4)
Fair value of plan assets					1,662.3	1,941.6		1,662.3	1,941.6	1,743.7
Payable to intermediary agent					67.7	76.1		67.7	76.1
Employer contributions								27.9	58.6
Pension obligation					2,001.2	2,370.5		2,001.2	2,370.5	2,516.2
Contributions by company								523.7	524.0	469.3
Pension | Safeway Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets					1,371.8			1,371.8
Pension | Shaw's Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets					252.3			252.3
Pension | United Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets					38.2			38.2
Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan gain (loss) due to settlement								0.0	0.0	0.0
Fair value of plan assets					0.0	0.0		0.0	0.0	0.0
Employer contributions								2.0	1.4
Pension obligation					19.0	$ 21.2		19.0	21.2	20.9
Multiemployer Health and Welfare Plans
Defined Benefit Plan Disclosure [Line Items]
Contributions by company								$ 1,200.0	$ 1,200.0	$ 1,200.0
Combined Plan
Defined Benefit Plan Disclosure [Line Items]
Required annual contribution		$ 23.2
Defined contribution plan, term		25 years
MAP And FELRA
Defined Benefit Plan Disclosure [Line Items]
Number of unions | union	2
Required annual contribution					1,200.0
Defined contribution plan, term								10 years
MAP And FELRA | Minimum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, term								25 years
MAP And FELRA | Maximum
Defined Benefit Plan Disclosure [Line Items]
Employer discretionary contribution amount in 401(k)								$ 13.7
MAP And FELRA | Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Non-cash pre-tax charge					106.3
Non-cash charge, net of tax					78.7
Pension obligation					$ 19.0			19.0
Variable Annuity Pension Plan (VAPP)
Defined Benefit Plan Disclosure [Line Items]
Non-cash pre-tax charge							$ 285.7	$ 4.0
Non-cash charge, net of tax			$ 213.0
Variable Annuity Pension Plan (VAPP) | Minimum
Defined Benefit Plan Disclosure [Line Items]
Transition reserve, amount paid			$ 8.0