CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Retained Earnings	Accumulated Other Comprehensive Loss	Common Stock	Additional Paid-In Capital	Non- Controlling Interests	Cumulative effect adjustment from adoption of new accounting standards	Cumulative effect adjustment from adoption of new accounting standards Retained Earnings	Cumulative effect adjustment from adoption of new accounting standards Accumulated Other Comprehensive Loss
Beginning balance at Jan. 31, 2019	$ 3,130.9	$ 2,045.6	$ (204.8)	$ 1.2	$ 1,275.4	$ 13.5	$ 21.8	$ 47.8	$ (26.0)
Beginning balance (shares) at Jan. 31, 2019				121.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units	2.6			$ 0.3	2.6
Shares withheld related to net share settlement of share-based compensation	(9.1)				(9.1)
Shares withheld related to net share settlement of share-based compensation (shares)				(0.1)
Share-based compensation expense	15.2				15.2
Purchase and retirement of Common Stock	$ (85.4)	(77.6)			(7.8)
Purchase and retirement of Common Stock (shares)	(0.9)			(0.9)
Cash dividends on Common Stock	$ (137.0)	(137.0)
Accrued dividends on share-based awards	(0.7)	(0.9)			0.2
Other comprehensive earnings, net of tax	(6.2)		(6.2)
Net earnings (loss)	261.5	261.5
Non-controlling interests	(0.5)					(0.5)
Ending balance at Jul. 31, 2019	$ 3,193.1	2,139.4	(237.0)	$ 1.2	1,276.5	13.0
Ending balance (shares) at Jul. 31, 2019	120.8			120.8
Beginning balance at Apr. 30, 2019	$ 3,172.0	2,128.3	(244.0)	$ 1.2	1,273.1	13.4
Beginning balance (shares) at Apr. 30, 2019				121.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units	0.6				0.6
Shares withheld related to net share settlement of share-based compensation	(1.0)				(1.0)
Share-based compensation expense	9.3				9.3
Purchase and retirement of Common Stock	$ (60.0)	(54.5)			(5.5)
Purchase and retirement of Common Stock (shares)	(0.6)			(0.6)
Cash dividends on Common Stock	$ (70.2)	(70.2)
Accrued dividends on share-based awards	(0.5)	(0.5)
Other comprehensive earnings, net of tax	7.0		7.0
Net earnings (loss)	136.3	136.3
Non-controlling interests	(0.4)					(0.4)
Ending balance at Jul. 31, 2019	$ 3,193.1	2,139.4	(237.0)	$ 1.2	1,276.5	13.0
Ending balance (shares) at Jul. 31, 2019	120.8			120.8
Beginning balance at Jan. 31, 2020	$ 3,335.4	2,207.6	(273.2)	$ 1.2	1,387.3	12.5	$ (2.5)	$ (2.5)
Beginning balance (shares) at Jan. 31, 2020	121.2			121.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units	$ 4.0			$ 0.3	4.0
Shares withheld related to net share settlement of share-based compensation	(10.3)				(10.3)
Shares withheld related to net share settlement of share-based compensation (shares)				(0.1)
Share-based compensation expense	14.0				14.0
Purchase and retirement of Common Stock	$ 0.0
Purchase and retirement of Common Stock (shares)	0.0
Cash dividends on Common Stock	$ (140.7)	(140.7)
Accrued dividends on share-based awards	0.1	(1.0)			1.1
Other comprehensive earnings, net of tax	41.0		41.0
Net earnings (loss)	(32.7)	(32.7)
Non-controlling interests	(0.6)					(0.6)
Ending balance at Jul. 31, 2020	$ 3,207.7	2,030.7	(232.2)	$ 1.2	1,396.1	11.9
Ending balance (shares) at Jul. 31, 2020	121.4			121.4
Beginning balance at Apr. 30, 2020	$ 3,181.0	2,069.7	(291.7)	$ 1.2	1,389.7	12.1
Beginning balance (shares) at Apr. 30, 2020				121.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units	0.3				0.3
Exercise of stock options and vesting of restricted stock units (shares)				0.1
Shares withheld related to net share settlement of share-based compensation	(0.4)				(0.4)
Share-based compensation expense	$ 6.4				6.4
Purchase and retirement of Common Stock (shares)	0.0
Cash dividends on Common Stock	$ (70.4)	(70.4)
Accrued dividends on share-based awards	(0.4)	(0.5)			(0.1)
Other comprehensive earnings, net of tax	59.5		59.5
Net earnings (loss)	31.9	31.9
Non-controlling interests	(0.2)					(0.2)
Ending balance at Jul. 31, 2020	$ 3,207.7	$ 2,030.7	$ (232.2)	$ 1.2	$ 1,396.1	$ 11.9
Ending balance (shares) at Jul. 31, 2020	121.4			121.4