Accounting for Share-Based Compensation 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Recognized share-based compensation
Share-based compensation expense before tax	$ 22	$ 20	$ 42	$ 40
Income tax benefit	(7)	(6)	(13)	(13)
Net share-based compensation expense	15	14	29	27
Costs of Licensing and Maintenance [Member]
Recognized share-based compensation
Share-based compensation expense before tax	1	1	2	2
Cost of Professional Services [Member]
Recognized share-based compensation
Share-based compensation expense before tax	1	1	2	2
Selling and Marketing [Member]
Recognized share-based compensation
Share-based compensation expense before tax	8	7	15	14
General and Administrative [Member]
Recognized share-based compensation
Share-based compensation expense before tax	7	6	13	12
Product Development and Enhancements [Member]
Recognized share-based compensation
Share-based compensation expense before tax	$ 5	$ 5	$ 10	$ 10