Business and Summary of Significant Accounting Policies - Stock Based Compensation Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 165.6	$ 132.2	$ 156.3
Tax benefit	(45.2)	(36.4)	(35.5)
Stock-based compensation expense related to stock awards and ESP Plan purchases, net	120.4	95.8	120.8
Cost of license and other revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	4.6	3.8	3.7
Cost of subscription
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	4.3	2.2	1.5
Marketing and sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	72.4	58.6	64.3
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	56.0	43.7	61.8
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 28.3	$ 23.9	$ 25.0