CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Non-controlling Interests [Member]
Beginning Balances at Jan. 31, 2015	$ 2,850.7	$ 1,950.7	$ (290.5)	$ 1.3	$ 1,173.6	$ 15.6
Beginning Balance, Shares at Jan. 31, 2015				129.3
Exercise of stock options and vesting of restricted stock units ("RSUs")	0.3	0.0	0.0	$ 0.0	0.3	0.0
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				0.3
Tax benefit from exercise of stock options and vesting of RSUs	2.1	0.0	0.0	$ 0.0	2.1	0.0
Share-based compensation expense	24.8	0.0	0.0	0.0	24.8	0.0
Purchase and retirement of Common Stock, Value	$ (220.4)	(198.7)	0.0	$ 0.0	(21.7)	0.0
Purchase and retirement of Common Stock, Shares	(2.8)			(2.8)
Cash dividends on Common Stock	$ (203.4)	(203.4)	0.0	$ 0.0	0.0	0.0
Other comprehensive earnings, net of tax	12.4	0.0	12.4	0.0	0.0	0.0
Net earnings	463.9	463.9	0.0	0.0	0.0	0.0
Redemption of non-controlling interest	(2.2)	0.0	0.0	0.0	(3.4)	1.2
Non-controlling interests	1.3	0.0	0.0	0.0	0.0	1.3
Ending Balances at Jan. 31, 2016	2,929.5	2,012.5	(278.1)	$ 1.3	1,175.7	18.1
Ending Balance, Shares at Jan. 31, 2016				126.8
Exercise of stock options and vesting of restricted stock units ("RSUs")	12.5	0.0	0.0	$ 0.0	12.5	0.0
Exercise of stock options and vesting of restricted stock units ("RSUs"), shares				0.5
Tax deficiency from exercise of stock options and vesting of RSUs	(0.5)	0.0	0.0	$ 0.0	(0.5)	0.0
Share-based compensation expense	24.5	0.0	0.0	0.0	24.5	0.0
Purchase and retirement of Common Stock, Value	$ (183.6)	(161.5)	0.0	$ (0.1)	(22.0)	0.0
Purchase and retirement of Common Stock, Shares	(2.8)			(2.8)
Cash dividends on Common Stock	$ (218.8)	(218.8)	0.0	$ 0.0	0.0	0.0
Other comprehensive earnings, net of tax	21.9	0.0	21.9	0.0	0.0	0.0
Net earnings	446.1	446.1	0.0	0.0	0.0	0.0
Non-controlling interests	(3.2)	0.0	0.0	0.0	0.0	(3.2)
Ending Balances 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			124.5
Exercise of stock options and vesting of restricted stock units ("RSUs")	$ 54.6	0.0	0.0	$ 0.0	54.6	0.0
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)	0.0	0.0	$ 0.0	(8.6)	0.0
Shares Paid for Tax Withholding for Share Based Compensation				(0.1)
Share-based compensation expense	28.2	0.0	0.0	$ 0.0	28.2	0.0
Purchase and retirement of Common Stock, Value	$ (99.2)	(90.8)	0.0	$ 0.0	(8.4)	0.0
Purchase and retirement of Common Stock, Shares	(1.0)			(1.0)
Cash dividends on Common Stock	$ (242.6)	(242.6)	0.0	$ 0.0	0.0	0.0
Dividends, Share-based Compensation	(0.8)	0.8	0.0	0.0	0.0	0.0
Other comprehensive earnings, net of tax	118.2	0.0	118.2	0.0	0.0	0.0
Net earnings	370.1	370.1	0.0	0.0	0.0	0.0
Non-controlling interests	(0.1)	0.0	0.0	0.0	0.0	(0.1)
Ending Balances 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