Financing Arrangement (Tables)

6 Months Ended

Sep. 30, 2012

Debt Instruments [Abstract]

Carrying Values Of Liability And Equity Components Of Notes

	As of September 30, 2012			As of March 31, 2012
Principal amount of Notes	$	633		$	633
Unamortized discount of the liability component	(84		)	(94		)
Net carrying amount of Notes	$	549		$	539
Equity component, net	$	105		$	105

Schedule Of Interest Expense Related To Notes

	Three Months Ended September 30,				Six Months Ended September 30,
	2012		2011		2012		2011
Amortization of debt discount	$	5	$	4	$	10	$	4
Amortization of debt issuance costs	1		1		2		1
Coupon interest expense	1		1		2		1
Total interest expense related to Notes	$	7	$	6	$	14	$	6