Guarantees (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Guarantor Obligations [Line Items]
Maximum Exposure of Guarantee	$ 8,325,000	$ 8,561,000
Carrying Amount of Liability	7,764,000	8,124,000
Guarantees (Textual) [Abstract]
Customer finance leases expire periodically	2014
Estimated outstanding assumed claims	7,000,000
Outstanding letter of credit provided by the purchaser	0
Contingent rentals associated with residual value guarantees [Member]
Guarantor Obligations [Line Items]
Maximum Exposure of Guarantee	91,000,000	113,000,000
Carrying Amount of Liability	4,000,000	4,000,000
Individual Customer Finance Leases [Member]
Guarantor Obligations [Line Items]
Maximum Exposure of Guarantee	800,000	2,000,000
Carrying Amount of Liability	$ 200,000	$ 1,000,000