Business And Summary Of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Nov. 12, 2019	Jan. 31, 2019
Accounting Policies [Abstract]
Accounts receivable sold	$ 921.0		$ 921.0			$ 1,100.0
Discount fees on sale of accounts receivable	$ 4.1	$ 4.1	$ 11.8	$ 10.5
Apple
Concentration Risk and Subsequent Events [Line Items]
Concentration Risk, Percentage	17.00%	17.00%	15.00%	15.00%
Cisco Systems, Inc.
Concentration Risk and Subsequent Events [Line Items]
Concentration Risk, Percentage	11.00%	10.00%	11.00%	11.00%
HP, Inc.
Concentration Risk and Subsequent Events [Line Items]
Concentration Risk, Percentage	10.00%	11.00%	11.00%	11.00%
Subsequent Event [Member]
Concentration Risk and Subsequent Events [Line Items]
Business Acquisition, Share Price					$ 145