Accounting for Share-Based Compensation 1 (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Recognized share-based compensation
Share-based compensation expense before tax	$ 26	$ 25	$ 80	$ 70
Income tax benefit	(8)	(8)	(26)	(22)
Net share-based compensation expense	18	17	54	48
Costs of Licensing and Maintenance
Recognized share-based compensation
Share-based compensation expense before tax	2	2	5	5
Cost of Professional Services
Recognized share-based compensation
Share-based compensation expense before tax	1	1	3	3
Selling and Marketing
Recognized share-based compensation
Share-based compensation expense before tax	9	9	28	25
General and Administrative
Recognized share-based compensation
Share-based compensation expense before tax	8	9	27	25
Product Development and Enhancements
Recognized share-based compensation
Share-based compensation expense before tax	$ 6	$ 4	$ 17	$ 12