Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Aug. 29, 2014
Other Liabilities [Abstract]
Lease liability	$ 5,900	$ 5,900
Liability for demolition costs	2,654	2,781
Accrued pension	684	2,907
Security deposit payable	75	91
Other	29
Other current liabilities	9,342	11,679
Straight-line rent liability	15,570	13,444
Lease make-good provision	5,612	5,648
Accrued pension	4,921	5,228	$ 7,500
Environmental reserve	1,656	1,656
Deferred revenue - real estate	9	18
Acquired leases	137	186
Other	441	469
Other liabilities	$ 28,346	$ 26,649