Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Aug. 29, 2014
Other Liabilities [Abstract]
Lease liability	$ 5,900
Liability for demolition costs	2,827	$ 2,783
Accrued pension	684	684
Security deposit payable	70	69
Finance lease liabilities	37	40
Other	41	43
Other current liabilities	9,559	3,619
Lease make-good provision	7,999	7,766
Accrued pension	3,490	3,605	$ 7,500
Deferred rent liability	3,410	3,930
Environmental reserve	1,656	1,656
Lease liability		5,900
Acquired leases	19	21
Finance lease liabilities	20	28
Other non-current liabilities	$ 16,594	$ 22,906