Supplemental Statement of Cash Flows Information (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Supplemental Cash Flow Information [Abstract]
Interest payments, net	$ 75	$ 75	$ 70
Income taxes paid, net from continuing operations	365	411	489
Excess tax benefits from share-based incentive awards included in financing activities from continuing operations	4	3	6
Share-based incentive awards, Non-cash financing activities	43	44	48
Withholding taxes on share-based incentive awards, Non-cash financing activities	28	28	28
Discretionary stock contributions to CA, Inc. Savings Harvest Plan, Non-cash financing activities	24	26	28
Treasury common shares issued in connection with Employee Stock Purchase Plan, Non-cash financing activities	$ 5	$ 5	$ 4