Finance Receivables (Details 1) $ in Thousands	Mar. 31, 2016 USD ($) tenant	Dec. 31, 2015 USD ($) tenant
Credit Quality Of Finanace Receivables:
Financing receivable	$ 544,979	$ 539,608
Internally Assigned Grade 1 | Net investments in direct financing lease
Credit Quality Of Finanace Receivables:
Number of tenants and obligors | tenant	0	0
Financing receivable	$ 0	$ 0
Internally Assigned Grade 2 | Net investments in direct financing lease
Credit Quality Of Finanace Receivables:
Number of tenants and obligors | tenant	1	1
Financing receivable	$ 2,264	$ 2,264
Internally Assigned Grade 3 | Net investments in direct financing lease
Credit Quality Of Finanace Receivables:
Number of tenants and obligors | tenant	10	10
Financing receivable	$ 430,054	$ 429,212
Internally Assigned Grade 4 | Net investments in direct financing lease
Credit Quality Of Finanace Receivables:
Number of tenants and obligors | tenant	5	4
Financing receivable	$ 112,661	$ 108,132
Internally Assigned Grade 5 | Net investments in direct financing lease
Credit Quality Of Finanace Receivables:
Number of tenants and obligors | tenant	0	0
Financing receivable	$ 0	$ 0