UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance, beginning of period at Dec. 31, 2022	$ 426,966	$ 5,783	$ 1,566	$ 23,706	$ 404,924	$ (9,013)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	564	161		403
Net income	5,692				5,692
Cash dividends on Class A and Class B common stock	(1,557)				(1,557)
Reclassification adjustment to net income, net of tax	21					21
Balance, end of period at Mar. 31, 2023	431,686	5,944	1,566	24,109	409,059	(8,992)
Balance, beginning of period at Dec. 31, 2023	382,340	5,883	1,566	28,672	355,873	(9,654)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	531	130		401
Purchase of treasury shares	(4,274)	(128)			(4,146)
Net income	4,570				4,570
Cash dividends on Class A and Class B common stock	(1,630)				(1,630)
Reclassification adjustment to net income, net of tax	76					76
Balance, end of period at Mar. 31, 2024	$ 381,613	$ 5,885	$ 1,566	$ 29,073	$ 354,667	$ (9,578)