Business and Summary of Significant Accounting Policies - Stock Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	$ 197.2	$ 165.6	$ 132.2
Tax benefit	(1.6)	(45.2)	(36.4)
Stock-based compensation expense related to stock awards and ESP Plan purchases, net	195.6	120.4	95.8
Cost of license and other revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	6.1	4.6	3.8
Cost of subscription
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	5.7	4.3	2.2
Marketing and sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	85.2	72.4	58.6
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	70.4	56.0	43.7
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	$ 29.8	$ 28.3	$ 23.9