Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Other Liabilities [Abstract]
Accrued pension	$ 684	$ 684
Security deposit payable	88	68
Finance lease liabilities	20	28
Other	32	33
Other current liabilities	824	813
Lease make-good provision	6,124	6,131
Accrued pension	3,017	3,138
Deferred rent liability	2,412	2,484
Environmental reserve	1,656	1,656
Lease liability	5,900	5,900
Acquired leases	10	11
Other non-current liabilities	$ 19,119	$ 19,320