Stock Plans 1 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Recognized share-based compensation
Share-based compensation expense before tax	$ 87	$ 81	$ 77
Income tax benefit	(28)	(26)	(25)
Net share-based compensation expense	59	55	52
Costs of Licensing and Maintenance
Recognized share-based compensation
Share-based compensation expense before tax	5	4	3
Cost of Professional Services
Recognized share-based compensation
Share-based compensation expense before tax	4	4	4
Selling and Marketing
Recognized share-based compensation
Share-based compensation expense before tax	30	28	30
General and Administrative
Recognized share-based compensation
Share-based compensation expense before tax	29	26	23
Product Development and Enhancements
Recognized share-based compensation
Share-based compensation expense before tax	$ 19	$ 19	$ 17