FINANCIAL STATEMENT SCHEDULE II (Details) - USD ($) $ in Millions		12 Months Ended
		Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year		$ 6.3	$ 4.9	$ 5.6
Valuation Allowances and Reserves, Charged to Cost and Expense		2.3	1.6	1.3
Deductions and Write-Offs		1.0	0.2	2.0
Balance at End of Year		7.6	6.3	4.9
Product returns reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year		2.6	4.0	4.9
Valuation Allowances and Reserves, Charged to Cost and Expense		10.4	17.4	23.1
Deductions and Write-Offs		11.4	18.8	24.0
Balance at End of Year		1.6	2.6	4.0
Partner Program reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	[1]	36.5	38.4	48.3
Valuation Allowances and Reserves, Charged to Cost and Expense	[1]	267.4	237.3	278.6
Deductions and Write-Offs	[1]	258.7	239.2	288.5
Balance at End of Year	[1]	45.2	36.5	38.4
Restructuring
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year		1.6	5.6	8.9
Valuation Allowances and Reserves, Charged to Cost and Expense		0.0	3.2	12.8
Deductions and Write-Offs		0.3	7.2	16.1
Balance at End of Year		$ 1.3	$ 1.6	$ 5.6

[1] The partner program reserves balance impacts "Accounts receivable, net" and "Accounts payable" on the accompanying Consolidated Balance Sheets.