Income Taxes Components of Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ 125.5	$ 175.8	$ 130.9
Current State and Local Tax Expense (Benefit)	15.4	22.3	18.2
Current Foreign Tax Expense (Benefit)	43.5	49.8	66.5
Current Income Tax Expense (Benefit)	184.4	247.9	215.6
Deferred Federal Income Tax Expense (Benefit)	36.7	(15.4)	25.2
Deferred State and Local Income Tax Expense (Benefit)	7.1	3.9	13.2
Deferred Foreign Income Tax Expense (Benefit)	2.3	9.6	(0.7)
Deferred Income Tax Expense (Benefit)	46.1	(1.9)	37.7
Income Tax Expense (Benefit)	$ 230.5	$ 246.0	$ 253.3