Trade and Installment Accounts Receivable (Tables)

3 Months Ended

Jun. 30, 2011

Trade and Installment Accounts Receivable [Abstract]

Components of trade and installment accounts receivable, net

	June 30,			March 31,
	2011			2011
	(in millions)
Accounts receivable — billed	$	535		$	758
Accounts receivable — unbilled		64			86
Other receivables		19			27
Less: Allowance for doubtful accounts		(21	)		(22	)
Trade and installment accounts receivable, net	$	597		$	849