Stock Plans 1 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Recognized share-based compensation
Share-based compensation expense before tax	$ 97	$ 87	$ 81
Income tax benefit	(31)	(28)	(26)
Net share-based compensation expense	66	59	55
Costs of Licensing and Maintenance
Recognized share-based compensation
Share-based compensation expense before tax	7	5	4
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	34	30	28
General and Administrative
Recognized share-based compensation
Share-based compensation expense before tax	35	29	26
Product Development and Enhancements
Recognized share-based compensation
Share-based compensation expense before tax	$ 17	$ 19	$ 19