Net Investment In Direct Finance Leases (Gross Finance Lease Receivables By Customer Categories) (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Gross finance lease receivables	[1]	$ 418,453	$ 412,489
Tier 1 [Member]
Financing Receivable, Recorded Investment [Line Items]
Gross finance lease receivables		372,524	366,629
Tier 2 [Member]
Financing Receivable, Recorded Investment [Line Items]
Gross finance lease receivables		45,929	45,860
Tier 3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Gross finance lease receivables

[1] At the inception of the lease, the Company records the total minimum lease payments, executory costs, if any, and unguaranteed residual value as gross finance lease receivables. The gross finance lease receivables are reduced as customer payments are received. There was $34.8 million and $34.4 million unguaranteed residual value at March 31, 2018 and December 31, 2017, respectively, included in gross finance lease receivables. There were no executory costs included in gross finance lease receivables as of March 31, 2018 and December 31, 2017.