Business and Summary of Significant Accounting Policies (Accounts Receivable) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Business and Summary of Significant Accounting Policies
Accounts Receivable Sold To and Held by Financial Institutions	$ 739.2	$ 1,100.0
Sale of Accounts Receivable, Discount Fees	$ 15.9	$ 14.9	$ 9.0