Financing Arrangement (Tables)

9 Months Ended

Dec. 31, 2012

Debt Instruments [Abstract]

Carrying Values Of Liability And Equity Components Of Notes

	As of December 31, 2012			As of March 31, 2012
Principal amount of Notes	$	633		$	633
Unamortized discount of the liability component	(79		)	(94		)
Net carrying amount of Notes	$	554		$	539
Equity component, net	$	105		$	105

Schedule Of Interest Expense

Interest expense recognized related to our financing arrangements are as follows (in millions):

	Three Months Ended December 31,				Nine Months Ended December 31,
	2012		2011		2012		2011
Amortization of debt discount	$	5	$	5	$	15	$	9
Amortization of debt issuance costs	—		—		2		1
Coupon interest expense	1		1		3		2
Other interest expense	1		1		1		1
Total interest expense	$	7	$	7	$	21	$	13