Receivables and Financing Arrangements (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended		12 Months Ended
	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015	Jan. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impairment charge		$ 0.0	$ 9.6
Consumer Credit Card Financing Receivables	$ 61.8	$ 70.9	$ 61.8
Consumer Credit Card Financing Receivables Percentage Current	97.00%	97.00%	97.00%
Consumer Credit Card Financing Receivable Allowance For Credit Losses	$ 1.0	$ 1.0	$ 1.0
Financing Receivables Gross Current	2.2	3.0	2.2
Financing Receivables Net Non Current	47.7	19.2	$ 47.7
Koidu Limited [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross		43.8
Impairment charge	$ 9.6			$ 37.9
Loans and Leases Receivable, Net Amount		$ 5.9		$ 5.9