CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Income Statement [Abstract]
Net sales	$ 747.1	$ 1,048.5	$ 1,302.6	$ 2,051.6
Cost of sales	285.5	390.8	532.0	774.7
Gross profit	461.6	657.7	770.6	1,276.9
Selling, general and administrative expenses	401.9	473.4	816.3	931.7
Earnings (loss) from operations	59.7	184.3	(45.7)	345.2
Interest expense and financing costs	11.1	9.8	20.9	20.2
Other income, net	(0.8)	(0.9)	(26.2)	(1.9)
Earnings (loss) from operations before income taxes	49.4	175.4	(40.4)	326.9
Provision (benefit) for income taxes	17.5	39.1	(7.7)	65.4
Net earnings (loss)	$ 31.9	$ 136.3	$ (32.7)	$ 261.5
Net earnings per share:
Basic (usd per share)	$ 0.26	$ 1.13	$ (0.27)	$ 2.16
Diluted (usd per share)	$ 0.26	$ 1.12	$ (0.27)	$ 2.15
Weighted-average number of common shares:
Basic (shares)	121.4	121.1	121.3	121.3
Diluted (shares)	121.7	121.4	121.3	121.6