CONSOLIDATED STATEMENT 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
Beginning balance at Jan. 31, 2016	$ 2,929.5	$ 2,012.5	$ (278.1)	$ 1.3	$ 1,175.7	$ 18.1
Beginning balance (shares) at Jan. 31, 2016				126.8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units (RSUs)	12.5				12.5
Exercise of stock options and vesting of restricted stock units (RSUs) (shares)				0.5
Tax effect of exercise of stock options and vesting of RSUs	(0.5)				(0.5)
Share-based compensation expense	24.5				24.5
Purchase and retirement of Common Stock	$ (183.6)	(161.5)		$ (0.1)	(22.0)
Purchase and retirement of Common Stock (shares)	(2.8)			(2.8)
Cash dividends on Common Stock	$ (218.8)	(218.8)
Other comprehensive earnings, net of tax	21.9		21.9
Net earnings	446.1	446.1
Non-controlling interests	(3.2)					(3.2)
Ending balance at Jan. 31, 2017	3,028.4	2,078.3	(256.2)	$ 1.2	1,190.2	14.9
Ending balance (shares) at Jan. 31, 2017				124.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units (RSUs)	54.6				54.6
Exercise of stock options and vesting of restricted stock units (RSUs) (shares)				1.1
Shares withheld related to net share settlement of share-based compensation	(8.6)				(8.6)
Shares withheld related to net share settlement of share-based compensation (shares)				(0.1)
Share-based compensation expense	28.2				28.2
Purchase and retirement of Common Stock	$ (99.2)	(90.8)			(8.4)
Purchase and retirement of Common Stock (shares)	(1.0)			(1.0)
Cash dividends on Common Stock	$ (242.6)	(242.6)
Other comprehensive earnings, net of tax	118.2		118.2
Net earnings	370.1	370.1
Non-controlling interests	(0.1)					(0.1)
Accrued dividends on share-based awards	(0.8)	(0.8)
Ending balance at Jan. 31, 2018	$ 3,248.2	2,114.2	(138.0)	$ 1.2	1,256.0	14.8
Ending balance (shares) at Jan. 31, 2018	124.5			124.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of restricted stock units (RSUs)	$ 23.1				23.1
Exercise of stock options and vesting of restricted stock units (RSUs) (shares)				0.6
Shares withheld related to net share settlement of share-based compensation	(8.6)				(8.6)
Shares withheld related to net share settlement of share-based compensation (shares)				(0.1)
Share-based compensation expense	34.1				34.1
Purchase and retirement of Common Stock	$ (421.4)	(392.1)			(29.3)
Purchase and retirement of Common Stock (shares)	(3.5)			(3.5)
Cash dividends on Common Stock	$ (263.8)	(263.8)
Other comprehensive earnings, net of tax	(68.6)		(68.6)
Net earnings	586.4	586.4
Non-controlling interests	(1.3)					(1.3)
Accrued dividends on share-based awards	(1.1)	(1.2)			0.1
Ending balance at Jan. 31, 2019	$ 3,130.9	$ 2,045.6	$ (204.8)	$ 1.2	$ 1,275.4	$ 13.5
Ending balance (shares) at Jan. 31, 2019	121.5			121.5