Net Investment in Finance Leases (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Gross finance lease receivables based on the company's internal customer credit rating
Gross finance lease receivables	$ 145,951,000	$ 152,321,000
Number of days gross finance lease were past due	31 days
[Tier1Member]
Gross finance lease receivables based on the company's internal customer credit rating
Gross finance lease receivables	106,582,000	109,883,000
Gross finance lease receivables past due	100,000
[Tier2Member]
Gross finance lease receivables based on the company's internal customer credit rating
Gross finance lease receivables	39,369,000	42,438,000
Gross finance lease receivables past due	$ 500,000