Supplemental Statement of Cash Flows Information 2 (Details) - USD ($) $ in Millions	6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Supplemental Cash Flow Information [Abstract]
Interest payments, net	$ 32	$ 40
Income taxes paid, net from continuing operations	131	181
Excess tax benefits from share-based incentive awards included in financing activities from continuing operations	3	3
Share-based incentive awards, Non-cash financing activities	41	42
Withholding taxes on share-based incentive awards, Non-cash financing activities	27	27
Discretionary stock contributions to CA, Inc. Savings Harvest Plan, Non-cash financing activities	24	26
Treasury common shares issued in connection with Employee Stock Purchase Plan, Non-cash financing activities	$ 2	$ 3