Accounting for Share-Based Compensation 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Recognized share-based compensation
Share-based compensation expense before tax	$ 21	$ 21	$ 41	$ 44
Income tax benefit	(6)	(8)	(13)	(16)
Net share-based compensation expense	15	13	28	28
Costs of Licensing and Maintenance [Member]
Recognized share-based compensation
Share-based compensation expense before tax	1	1	2	1
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	8	15	18
General and Administrative [Member]
Recognized share-based compensation
Share-based compensation expense before tax	6	7	12	15
Product Development and Enhancements [Member]
Recognized share-based compensation
Share-based compensation expense before tax	$ 5	$ 4	$ 10	$ 8