Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Aug. 29, 2014
Other Liabilities [Abstract]
Lease liability	$ 5,900	$ 5,900
Liability for demolition costs	2,600	2,781
Accrued pension	684	2,907
Security deposit payable	84	91
Other	6
Other current liabilities	9,274	11,679
Straight-line rent	15,713	13,444
Lease make-good provision	5,611	5,648
Accrued pension	4,795	5,228	$ 7,500
Environmental reserve	1,656	1,656
Deferred revenue - real estate	5	18
Acquired leases	114	186
Other	378	469
Other liabilities	$ 28,272	$ 26,649