Other Liabilities (Summary Of Other Liabilities Including Pension) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Other Liabilities [Abstract]
Lease liability	$ 5,900
Accrued pension	684	$ 684
Security deposit payable	53	68
Finance lease liabilities	3	28
Other	33	33
Other current liabilities	6,673	813
Lease make-good provision	5,860	6,131
Accrued pension	2,771	3,138
Deferred rent liability	1,537	2,484
Environmental reserve	1,656	1,656
Lease liability		5,900
Acquired leases	5	11
Other non-current liabilities	$ 11,829	$ 19,320