Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Class A [Member] Retained Earnings [Member]	Common Class A [Member] AOCI Attributable to Parent [Member]	Common Class A [Member] Common Stock, Common Class A [Member]	Common Class A [Member] Common Stock, Common Class B [Member]	Common Class A [Member] Treasury Stock, Common [Member]	Common Class A [Member] Additional Paid-in Capital [Member]	Common Class A [Member]	Common Class B [Member] Retained Earnings [Member]	Common Class B [Member] AOCI Attributable to Parent [Member]	Common Class B [Member] Common Stock, Common Class A [Member]	Common Class B [Member] Common Stock, Common Class B [Member]	Common Class B [Member] Treasury Stock, Common [Member]	Common Class B [Member] Additional Paid-in Capital [Member]	Common Class B [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Common Stock, Common Class A [Member]	Common Stock, Common Class B [Member]	Treasury Stock, Common [Member]	Additional Paid-in Capital [Member]	Total
Balance at Dec. 31, 2021															$ 187,935	$ (18,863)	$ 214	$ 1,038	$ 0	$ 38,419	$ 208,743
Net earnings							$ 8,598							$ 44,091	52,689	0	0	0	0	0	52,689
Cash dividends declared on common stock	$ (514)	$ 0	$ 0	$ 0	$ 0	$ 0	(514)	$ (2,922)	$ 0	$ 0	$ 0	$ 0	$ 0	(2,922)
Issuance of restricted common stock															0	0	0	33	0	(33)	0
Forfeiture of restricted common stock															0	0	0	(4)	0		0
Forfeiture of restricted common stock, APIC																				4
Repurchase of treasury stock															0	0	0	0	(349)	0	(349)
Foreign currency translation adjustment, net of taxes															0	(8,196)	0	0	0	0	(8,196)
Unrealized gains on interest rate swap cash flow hedge, net of taxes of $0															0	5,655	0	0	0	0	5,655
Unrealized holding losses on marketable securities, net of taxes of $0															0	(11)	0	0	0	0	(11)
Stock-based compensation expense															0	0	0	0	0	2,382	2,382
Change in unfunded SERP liability, net of taxes															0	4,869	0	0	0	0	4,869
Balance at Dec. 31, 2022															237,188	(16,546)	214	1,067	(349)	40,772	262,346
Net earnings							11,830							62,001	73,831	0	0	0	0	0	73,831
Cash dividends declared on common stock	$ (512)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (512)	$ (2,997)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (2,997)
Issuance of restricted common stock															0	0	0	1	0	(1)	0
Forfeiture of restricted common stock															0	0	0	(3)	0		0
Forfeiture of restricted common stock, APIC																				3
Repurchase of treasury stock															0	0	0	0	(105)	0	(105)
Foreign currency translation adjustment, net of taxes															0	6,684	0	0	0	0	6,684
Unrealized gains on interest rate swap cash flow hedge, net of taxes of $0															0	(1,579)	0	0	0	0	(1,579)
Unrealized holding losses on marketable securities, net of taxes of $0															0	1	0	0	0	0	1
Stock-based compensation expense															0	0	0	0	0	3,486	3,486
Change in unfunded SERP liability, net of taxes															0	(597)	0	0	0	0	(597)
Balance at Dec. 31, 2023															$ 307,510	$ (12,037)	$ 214	$ 1,065	$ (454)	$ 44,260	$ 340,558