EMPLOYEE BENEFIT PLANS AND COLLECTIVE BARGAINING AGREEMENTS - Schedule of Components of Net Pension and Post-retirement Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Feb. 27, 2021	Feb. 29, 2020
Pension
Components of net (income) expense:
Estimated return on plan assets	$ (103.9)	$ (110.1)
Service cost	15.7	14.7
Interest cost	48.6	80.6
Amortization of prior service cost	0.2	0.4
Amortization of net actuarial loss (gain)	2.0	0.5
(Income) loss due to settlement accounting	(0.7)	7.4
(Income) expense, net	(38.1)	(6.5)
Changes in plan assets and benefit obligations recognized in Other comprehensive income (loss):
Net actuarial (gain) loss	(245.8)	318.9
Settlement income (loss)	0.7	(7.4)
Amortization of net actuarial (loss) gain	(2.0)	(0.5)
Prior service cost	0.0	(1.1)
Amortization of prior service cost	(0.2)	(0.4)
Total recognized in Other comprehensive income (loss)	(247.3)	309.5
Total net expense and changes in plan assets and benefit obligations recognized in Other comprehensive income (loss)	(285.4)	303.0
Other Post-Retirement Benefits
Components of net (income) expense:
Estimated return on plan assets	0.0	0.0
Service cost	0.0	0.6
Interest cost	0.4	0.7
Amortization of prior service cost	1.9	3.7
Amortization of net actuarial loss (gain)	(0.6)	(0.5)
(Income) loss due to settlement accounting	0.0	0.0
(Income) expense, net	1.7	4.5
Changes in plan assets and benefit obligations recognized in Other comprehensive income (loss):
Net actuarial (gain) loss	1.3	(2.6)
Settlement income (loss)	0.0	0.0
Amortization of net actuarial (loss) gain	0.6	0.5
Prior service cost	0.0	0.0
Amortization of prior service cost	(1.9)	(3.7)
Total recognized in Other comprehensive income (loss)	0.0	(5.8)
Total net expense and changes in plan assets and benefit obligations recognized in Other comprehensive income (loss)	$ 1.7	$ (1.3)