Portfolio Quality - Non-Performing Assets (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Equipment under operating leases, net	$ 166	$ 23
Assets held for sale	235	471
Non performing assets held for sale	$ 31

Property subject to or available for operating lease net non accrual status.

No definition available.

Name:	ck0000711513_PropertySubjectToOrAvailableForOperatingLeaseNetNonAccrualStatus
Namespace Prefix:	ck0000711513_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant