CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 30, 2021	Feb. 01, 2020	Jan. 30, 2021	Feb. 01, 2020
Statement of Comprehensive Income [Abstract]
Recognition of pension and other postretirement benefit obligations, tax expense (benefit)	$ (0.1)	$ 2.4	$ (0.2)	$ 2.6
Recognition of interest rate swap cash flow hedges, tax expense (benefit)	3.2	(1.3)	7.4	(2.5)
Recognition of other cash flow derivatives, tax expense (benefit)	$ 0.1	$ 0.0	$ 0.0	$ 0.0