Significant Accounting Policies 2 (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Sep. 30, 2010	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Significant Accounting Policies [Abstract]
Gain on sale of equity investment	$ 10
Foreign currency transaction gain (losses)		(4)	(18)	(10)
Percentage of cash and cash equivalents held by the company's foreign subsidiaries outside the United States		64.00%	47.00%
Interest income		30	24	26
Total amount of restricted cash		56	56
Minimum restricted cash balance		$ 50
Purchased Software [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated amortized period, minimum years		3
Estimated amortized period, maximum years		10
Capitalized Software [Member]
Finite-Lived Intangible Assets [Line Items]
Capitalized software		5
Other Finite Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated amortized period, minimum years		2
Estimated amortized period, maximum years		12
Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Estimated minimum useful Life		3
Estimated maximum useful Life		7
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated minimum useful Life		5
Estimated maximum useful Life		40