EMPLOYEE BENEFIT PLANS AND COLLECTIVE BARGAINING AGREEMENTS - Narrative (Details) $ in Millions						3 Months Ended			12 Months Ended
	Dec. 18, 2022 USD ($)	Aug. 08, 2022 USD ($)	Dec. 20, 2021 union	Dec. 31, 2020 USD ($)	Jul. 01, 2020 USD ($) union	Feb. 25, 2023 USD ($) plan employee	Feb. 26, 2022 USD ($)	Dec. 04, 2021 USD ($)	Feb. 25, 2023 USD ($) plan employee	Feb. 26, 2022 USD ($)	Feb. 27, 2021 USD ($)	Apr. 25, 2023 employee
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, transferred									$ 203.5
Defined benefit pension obligation									205.4
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]										Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Defined benefit plan gain (loss) due to settlement										$ 11.1
Employer contributions									27.3	29.8	$ 60.0
Expected employer contribution next fiscal year						$ 18.0			$ 18.0
Number of multiemployer plans | plan						27			27
Number of unions | union					9
Employer discretionary contribution amount in 401(k)									$ 89.3	75.5	85.8
Non-cash pre-tax charge							$ 607.2
Non-cash charge, net of tax							449.4
Additional funding		$ 120.0
Amount paid									73.6		147.3
Accrued interest									$ 4.4		4.4
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						115,000			115,000
Number of employee scheduled to expire in collective bargaining agreements | employee						28,000			28,000
Accrued retention bonus						$ 5.3			$ 5.3
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Number of participants in collective bargaining agreements | employee												1,200
Merger Agreement
Defined Benefit Plan Disclosure [Line Items]
Aggregate retention program amount	$ 100.0
Merger Agreement | Last day on year granted
Defined Benefit Plan Disclosure [Line Items]
Award vesting rights, percentage	50.00%
Business combination termination, award vesting rights, percentage	50.00%
Merger Agreement | Next twelve months
Defined Benefit Plan Disclosure [Line Items]
Award vesting rights, percentage	50.00%
Payment period	6 months
Business combination termination, award vesting rights, percentage	50.00%
Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan gain (loss) due to settlement									0.6	16.2	0.7
Fair value of plan assets						1,407.3	1,662.3		1,407.3	1,662.3	1,941.6
Payable to intermediary agent						51.6	67.7		51.6	67.7
Employer contributions									25.8	27.9
Pension obligation						1,697.5	2,001.2		1,697.5	2,001.2	2,370.5
Contributions by company									546.5	523.7	524.0
Pension | Safeway Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets						1,147.7			1,147.7
Pension | Shaw's Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets						215.1			215.1
Pension | United Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets						28.0			28.0
Pension | Safeway VAPP
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets						16.5			16.5
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									1.5	2.0
Non-cash pre-tax charge									19.0
Pension obligation						12.4	$ 19.0		12.4	19.0	21.2
Multiemployer Health and Welfare Plans
Defined Benefit Plan Disclosure [Line Items]
Contributions by company									$ 1,300.0	$ 1,200.0	$ 1,200.0
Combined Plan
Defined Benefit Plan Disclosure [Line Items]
Required annual contribution				$ 23.2
Defined contribution plan, term (in years)				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 (in years)									10 years
MAP And FELRA | Minimum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, term (in years)									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
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