Fair Value Measurements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Fair Value, Option, Quantitative Disclosures [Line Items]
Percentage of inverse relationship to fair value	2.11%
Fair value of Equipment under operating leases changed classification to Assets held for sale or re-lease	$ 7
Net of allowance for losses	$ 24	$ 27

A valuation allowance for financing receivables that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953423-111524

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant