OTHER COMPREHENSIVE INCOME OR LOSS - Changes in the AOCI Balance (Details) - USD ($) $ in Millions	12 Months Ended
	Feb. 29, 2020	Feb. 23, 2019	Feb. 24, 2018	Jun. 15, 2019	Feb. 24, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning AOCI balance	$ 1,450.7	$ 1,398.2
Cumulative effect of accounting change					$ 574.6
Other comprehensive (loss) income before reclassifications	(356.2)	(129.8)
Amounts reclassified from Accumulated other comprehensive (loss) income	46.9	(5.6)
Tax benefit (expense)	82.9	35.6
Other comprehensive (loss) income	(209.8)	(99.8)	$ 203.9
Ending AOCI balance	2,278.1	1,450.7	1,398.2
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning AOCI balance	91.3	191.1
Cumulative effect of accounting change					16.6
Ending AOCI balance	(118.5)	91.3	191.1
Interest rate swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning AOCI balance	3.4	18.9
Other comprehensive (loss) income before reclassifications	(45.8)	(18.6)
Amounts reclassified from Accumulated other comprehensive (loss) income	35.4	(2.3)
Tax benefit (expense)	5.8	5.4
Other comprehensive (loss) income	(3.4)	(15.5)
Ending AOCI balance	0.0	3.4	18.9
Pension and Post-retirement benefit plan items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning AOCI balance	88.8	171.9
Other comprehensive (loss) income before reclassifications	(315.2)	(110.0)
Amounts reclassified from Accumulated other comprehensive (loss) income	11.5	(2.7)
Tax benefit (expense)	78.3	29.6
Other comprehensive (loss) income	(210.5)	(83.1)
Ending AOCI balance	(121.7)	88.8	171.9
Foreign currency translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning AOCI balance	(1.4)	(1.1)
Other comprehensive (loss) income before reclassifications	0.3	(0.3)
Amounts reclassified from Accumulated other comprehensive (loss) income	0.0	0.0
Tax benefit (expense)	0.0	0.0
Other comprehensive (loss) income	0.3	(0.3)
Ending AOCI balance	(1.1)	(1.4)	(1.1)
Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning AOCI balance	0.5	1.4
Other comprehensive (loss) income before reclassifications	4.5	(0.9)
Amounts reclassified from Accumulated other comprehensive (loss) income	0.0	(0.6)
Tax benefit (expense)	(1.2)	0.6
Other comprehensive (loss) income	3.8	(0.9)
Ending AOCI balance	$ 4.3	$ 0.5	$ 1.4
Accounting Standards Update 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of accounting change				$ 16.6	16.6
Accounting Standards Update 2018-02 | Interest rate swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of accounting change					1.2
Accounting Standards Update 2018-02 | Pension and Post-retirement benefit plan items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of accounting change					14.9
Accounting Standards Update 2018-02 | Foreign currency translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of accounting change					0.0
Accounting Standards Update 2018-02 | Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of accounting change					$ 0.5