Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Aug. 29, 2014
Other Liabilities [Abstract]
Lease liability	$ 5,900		$ 5,900
Liability for demolition costs	2,548		2,630
Accrued pension	684		684
Security deposit payable	83		84
Finance lease liabilities	117
Other	7		7
Other current liabilities	9,339		9,305
Straight-line rent			16,362
Lease make-good provision	5,930		5,614
Accrued pension	4,571		4,670	$ 7,500
Environmental reserve	1,656		1,656
Deferred revenue - real estate			32
Acquired leases	38		91
Finance lease liabilities	128
Other	7		506
Other liabilities	$ 12,330	$ 12,898	$ 28,931