Summary of Significant Accounting Policies Receivables and Financing Arrangements (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jan. 31, 2016	Jul. 31, 2015	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan impairment charges	$ 28.3	$ 9.6	$ 37.9	$ 0.0	$ 0.0
Consumer Credit Card Financing Receivables	$ 75.2		$ 75.2	$ 63.9
Consumer Credit Card Financing Receivables Percentage Current	97.00%		97.00%	98.00%
Consumer Credit Card Financing Receivable Allowance For Credit Losses	$ 1.0		$ 1.0	$ 1.0
Financing Receivables Gross Current	2.1		2.1	18.6
Financing Receivables Gross Non Current	18.9		18.9	$ 40.7
Koidu Limited [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross	43.8		43.8
Loan impairment charges	28.3	$ 9.6
Loans and Leases Receivable, Net Amount	$ 5.9		$ 5.9