Stock Plans 2 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2012 Y
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Costs	$ 96
Weighted Average Period Expected to Recognized	2.0
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Costs	12
Weighted Average Period Expected to Recognized	1.9
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Costs	52
Weighted Average Period Expected to Recognized	1.8
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Costs	28
Weighted Average Period Expected to Recognized	2.3
Stock Option Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Costs	$ 4
Weighted Average Period Expected to Recognized	1.9