Accounting Policies 2 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Accounting Policies (Textual) [Abstract]
Percentage of cash and cash equivalents held by the company's foreign subsidiaries outside the United States	64.00%
Interest payments	$ 26	$ 25
Income and other taxes paid, net	125	198
Excess tax benefits from options exercised included in financing activities from continuing operations	5	3
Share based incentive awards	57	51
Withholding taxes on share based incentive awards	30	25
Discretionary stock contributions to CA, Inc. Savings Harvest Plan	29	13
Intellectual property assets transaction value included in other gains expenses net	35
Notional Pooling Arrangement [Member]
Accounting Policies (Additional Textual) [Abstract]
Borrowings	253	154
Repayments	$ (247)	$ (86)