Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Gain on sale of equity investment		$ 10
Percentage of cash and cash equivalents held by the company's foreign subsidiaries outside the United States	64.00%
Interest payments	56	67
Income and other taxes paid, net	252	161
Share based incentive awards	54	63
Withholding taxes on share based incentive awards	26	27
Discretionary stock contributions to CA, Inc. Savings Harvest Plan	13	25
Notional Pooling Arrangement [Member]
Line of Credit Facility [Line Items]
Line of credit facility, amount outstanding	120
Proceeds from lines of credit	240
Repayments of lines of credit	$ 112