Receivables - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended		12 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2012	Jun. 30, 2013 Institution	Jun. 06, 2013 Agreement	Dec. 31, 2012	Mar. 31, 2012 Minimum [Member]	Mar. 31, 2013 Maximum [Member]	Mar. 31, 2012 Maximum [Member]
Schedule Of Financial Receivables [Line Items]
Number of arrangement with different financial institution to sell customer receivables			3
Asset Servicing value		$ 0
Liability servicing value		0
Funding of customer receivables sold					50		250
Funding of customer receivables sold after amendment						500
Deferred purchase price receivable	254
Additional funding received		5		205
Purchase price receivable		377
Number of additional financial institution		2
Amount of cash draws under arrangement		288
Amount of cash repayments under arrangement		283
Accounts receivables		6,650
Cash collections		$ 6,063