Business And Summary Of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Jan. 31, 2018
Accounting Policies [Abstract]
Accounts receivable sold	$ 627.7		$ 687.2
Discount fees on sale of accounts receivable	$ 2.7	$ 1.7