Accounting Policies 2 (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Accounting Policies (Textual) [Abstract]
Percentage of cash and cash equivalents held by the company's foreign subsidiaries outside the United States	73.00%
Interest payments, net	$ 31	$ 30
Income and other taxes paid, net	150	221
Excess tax benefits from options exercised included in financing activities from continuing operations	5	3
Share-based incentive awards	62	53
Withholding taxes on share-based incentive awards	34	26
Discretionary stock contributions to CA, Inc. Savings Harvest Plan	29	13
Other (Gains) Expenses, Net [Member]
Accounting Policies [Line Items]
Intellectual Property Assets Transaction Value	$ 35