Income Tax Considerations (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Impairment loss	$ 4,732	$ 7,220
Allowance on other assets	3	15
Interest expense	0	5,703
Net operating loss carryforwards	11,132	7,428
Straight-line rentals	1,391	916
Book-tax basis differential	1,800	1,676
Other	198	188
Total deferred tax assets	19,256	23,146
Valuation allowance	(12,787)	(15,587)
Total deferred tax assets, net of allowance	6,469	7,559
Deferred tax liabilities:
Book-tax basis differential	6,005	6,618
Other	398	517
Total deferred tax liabilities	6,403	$ 7,135
Deferred tax assets, operating loss carryforwards, subject to expiration	35,400
Deferred tax assets, operating loss carryforwards, not subject to expiration	$ 17,600