EMPLOYEE BENEFIT PLANS - Narrative (Details) $ in Millions			4 Months Ended
	Jul. 01, 2020 USD ($) installment union	Mar. 05, 2020 USD ($)	Jun. 20, 2020 USD ($)	Jun. 15, 2019 USD ($)	Jul. 21, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Contribution made to defined benefit plan			$ 54.6	$ 5.2
Expected future employer contributions for remainder of the fiscal year			7.8
Defined contribution plan costs recognized			21.8	$ 18.6
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]
Defined contribution plan costs recognized			$ 26.2
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Number of local unions ratifying the agreement | union	9
Subsequent Event | Variable Annuity Pension Plan (VAPP)
Defined Benefit Plan Disclosure [Line Items]
Expected future employer contributions	$ 286.0
Period of expected future employer contributions	3 years
Plan pre-funding period	30 days
Expected future employer contributions, after-tax	$ 213.0
Subsequent Event | Minimum | Variable Annuity Pension Plan (VAPP)
Defined Benefit Plan Disclosure [Line Items]
Number of installments for expected future employer contribution | installment	3
Pre-funded reserve amount					$ 8.0
Subsequent Event | Maximum | Variable Annuity Pension Plan (VAPP)
Defined Benefit Plan Disclosure [Line Items]
Number of installments for expected future employer contribution | installment	4
Pre-funded reserve amount					$ 9.0