Business And Summary Of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Jan. 31, 2017
Accounting Policies [Abstract]
Accounts receivable sold	$ 516.0		$ 506.7
Discount fees on sale of accounts receivable	$ 1.7	$ 1.2