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 [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 [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 [Member]	Additional Paid-in Capital [Member]	Total
Balance at Dec. 31, 2020															$ 166,491	$ (18,063)	$ 214	$ 1,021	$ 0	$ 36,136	$ 185,799
Net earnings							$ 4,076							$ 20,745	24,821	0	0	0	0	0	24,821
Cash dividends declared on common stock	$ (515)	$ 0	$ 0	$ 0	$ 0	$ 0	(515)	$ (2,862)	$ 0	$ 0	$ 0	$ 0	$ 0	(2,862)
Issuance of restricted common stock															0	0	0	21	0	(21)	0
Forfeiture of restricted common stock															0	0	0	(4)			0
Forfeiture of restricted common stock, APIC																			0	4
Foreign currency translation adjustment, net of taxes															0	(1,769)	0	0	0	0	(1,769)
Unrealized losses on interest rate swap cash flow hedge, net of taxes															0	(116)	0	0	0	0	(116)
Unrealized holding gains on marketable securities, net of taxes															0	10	0	0	0	0	10
Stock-based compensation expense															0	0	0	0	0	2,300	2,300
Change in unfunded SERP liability, net of taxes															0	1,075	0	0	0	0	1,075
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
Forfeiture of restricted common stock, APIC																			0	4
Foreign currency translation adjustment, net of taxes															0	(8,196)	0	0	0	0	(8,196)
Unrealized losses on interest rate swap cash flow hedge, net of taxes															0	5,655	0	0	0	0	5,655
Unrealized holding gains on marketable securities, net of taxes															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
Repurchase of treasury stock																			(349)		(349)
Balance at Dec. 31, 2022															$ 237,188	$ (16,546)	$ 214	$ 1,067	$ (349)	$ 40,772	$ 262,346