Summary of Significant Accounting Policies (Details 2) (Equipment on operating leases)	12 Months Ended
Dec. 31, 2012
Minimum
Depreciation
Lease term used to calculate depreciation	1 year
Maximum
Depreciation
Lease term used to calculate depreciation	7 years

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration