Net Investment in Finance Leases (Details 2) $ in Thousands	Dec. 31, 2017 USD ($)
Leases, Capital [Abstract]
Capital Leases, Future Minimum Payments Receivable, Next Twelve Months	$ 76,237
Capital Leases, Future Minimum Payments, Receivable in Two Years	70,776
Capital Leases, Future Minimum Payments, Receivable in Three Years	81,184
Capital Leases, Future Minimum Payments, Receivable in Four Years	46,372
Capital Leases, Future Minimum Payments, Receivable in Five Years	40,861
Capital Leases, Future Minimum Payments, Receivable Due Thereafter	32,504
Future minimum lease payment receivable (1)	$ 347,934