Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Aug. 29, 2014
Other Liabilities [Abstract]
Lease liability	$ 5,900		$ 5,900
Liability for demolition costs	2,664		2,630
Accrued pension	684		684
Security deposit payable	88		84
Finance lease liability	162
Other	27		7
Other current liabilities	9,525		9,305
Straight-line rent			16,362
Lease make-good provision	5,722		5,614
Accrued pension	4,544		4,670	$ 7,500
Environmental reserve	1,656		1,656
Deferred revenue - real estate	9		32
Acquired leases	47		91
Finance lease liabilities	169
Other	199		506
Other liabilities	$ 12,346	$ 12,898	$ 28,931