Investment in Lease Financing (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Rental receivable, net of principal and interest on nonrecourse debt	$ 3,757		$ 3,775
Estimated residual value of leased assets	772		900
Initial direct cost, net of amortization	16		16
Gross investment in lease financing	4,545		4,691
Unearned income	(942)		(1,040)
Net investment in lease financing	$ 3,603	[1]	$ 3,651	[1]

[1] a) The accumulated allowance for uncollectible minimum lease payments was $79 million and $112 million at December 31, 2011 and 2010, respectively