Other Commitments And Contingent Liabilities (Tables) (Average Wholesale Price Litigation [Member])

12 Months Ended

Mar. 31, 2012

Average Wholesale Price Litigation [Member]

Loss Contingencies [Line Items]

Litigation Reserve And Expense

	Years Ended March 31,
(In millions)		2012			2011			2010
AWP litigation reserve at beginning of period	$	330		$	143		$	143
Charges incurred		149			213			0
Payments made		(26	)		(26	)		0
AWP litigation reserve at end of period	$	453		$	330		$	143