FINANCIAL STATEMENT SCHEDULE II (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Partner Program reserves
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	$ 51.7	$ 36.5	$ 28.1
Additions Charged to Costs and Expenses or Revenues	453.7	294.7	224.3
Deductions and Write-Offs	445.0	279.5	215.9
Balance at End of Year	60.4	51.7	36.5
Restructuring and other facility exit costs
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of Year	2.1	57.2	8.4
Additions Charged to Costs and Expenses or Revenues	0.3	41.9	94.1
Deductions and Write-Offs	2.4	97.0	45.3
Balance at End of Year	$ 0.0	$ 2.1	$ 57.2