Components of Income from Leveraged Leases (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Operating Leases [Line Items]
Pre-tax income	$ 34	$ 30	$ 61
Income tax expense	$ 12	$ 12	$ 24

The tax effect from the current year income from arrangements meeting the criteria for classification as a leveraged lease.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=7662751&loc=d3e45152-112736

Name:	us-gaap_LeveragedLeasesIncomeStatementIncomeTaxExpenseOnLeveragedLeases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration