Stock-based Compensation Expense Stock Based Compensation Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense related to stock awards and ESP Plan purchases	$ 39.8	$ 31.1	$ 73.4	$ 64.6
Tax benefit	(10.4)	(8.1)	(19.6)	(17.4)
Stock-based compensation expense related to stock awards and ESP Plan purchases, net of tax	29.4	23.0	53.8	47.2
Cost of license and other revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense (in usd)	1.1	0.9	2.0	1.8
Cost of subscription
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense (in usd)	1.0	0.5	1.8	1.1
Marketing and sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense (in usd)	17.6	14.0	31.6	28.1
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense (in usd)	13.7	10.2	24.6	21.1
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense (in usd)	$ 6.4	$ 5.5	$ 13.4	$ 12.5