Business and Summary of Significant Accounting Policies (Accounts Receivable) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Business and Summary of Significant Accounting Policies
Accounts Receivable Sold To and Held by Financial Institutions	$ 1,100.0	$ 700.0
Sale of Accounts Receivable, Discount Fees	$ 14.9	$ 9.0	$ 6.1