Shareholders' Equity - Summary of common shareholders' equity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Shareholders' Equity
Beginning balance	$ 35,112	$ 35,366
Retirement benefits adjustment	49	1,672
Stock based compensation	120	191
Net Income (Loss)	(10,787)	(2,117)
Ending balance	24,494	35,112
Retained earnings
Shareholders' Equity
Beginning balance	23,741	25,858
Net Income (Loss)	(10,787)	(2,117)
Ending balance	12,954	23,741
Accumulated Other Comprehensive Loss
Shareholders' Equity
Beginning balance	(2,337)	(3,908)
Retirement benefits adjustment	(52)	1,571
Ending balance	(2,389)	(2,337)
Common Stock
Shareholders' Equity
Beginning balance	523	523
Stock based compensation	2
Ending balance	525	523
Capital in excess of par value
Shareholders' Equity
Beginning balance	14,556	14,500
Stock based compensation	61	56
Ending balance	14,617	14,556
ESOT
Shareholders' Equity
Beginning balance	(157)	(258)
Retirement benefits adjustment	101	101
Ending balance	(56)	(157)
Treasury stock
Shareholders' Equity
Beginning balance	(1,214)	(1,349)
Stock based compensation	57	135
Ending balance	$ (1,157)	$ (1,214)