Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ 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, 2022															$ 237,188	$ (16,546)	$ 214	$ 1,067	$ (349)	$ 40,772	$ 262,346
Balance (in shares) at Dec. 31, 2022																	2,142	10,643
Net earnings							$ 2,331							$ 12,241	14,572	0	$ 0	$ 0	0	0	14,572
Cash dividends declared on common stock	$ (128)	$ 0	$ 0	$ 0	$ 0	$ 0	(128)	$ (747)	$ 0	$ 0	$ 0	$ 0	$ 0	(747)
Forfeiture of restricted common stock															0	0	$ 0	$ (1)	0		0
Forfeiture of restricted common stock (in shares)																	0	(10)
Forfeiture of restricted common stock (in shares)																	(0)	10
Forfeiture of restricted common stock															0	0	$ 0	$ (1)	0		0
Forfeiture of restricted common stock																				1
Foreign currency translation adjustment, net of taxes of $26															0	1,998	0	0	0	0	1,998
Unrealized holding gains on interest rate swap cash flow hedge, net of taxes of $0															0	(894)	0	0	0	0	(894)
Unrealized holding gains on marketable securities, net of taxes of $0															0	1	0	0	0	0	1
Stock-based compensation expense															0	0	0	0	0	902	902
Change in unfunded SERP liability, net of taxes of ($4)															0	13	0	0	0	0	13
Balance at Mar. 31, 2023															250,885	(15,428)	$ 214	$ 1,066	(349)	41,675	278,063
Balance (in shares) at Mar. 31, 2023																	2,142	10,633
Balance at Dec. 31, 2023															307,510	(12,037)	$ 214	$ 1,065	(454)	44,260	340,558
Balance (in shares) at Dec. 31, 2023																	2,142	10,620
Net earnings							2,545							13,329	15,874	0	$ 0	$ 0	0	0	15,874
Cash dividends declared on common stock	$ (129)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (129)	$ (747)	$ 0	$ 0	$ 0	$ 0	$ 0	$ (747)
Issuance of restricted common stock															0	0	$ 0	$ 6	$ 0	(6)	0
Issuance of restricted common stock (in shares)																	0	58
Forfeiture of restricted common stock															0	0	$ 0	$ (6)			0
Forfeiture of restricted common stock (in shares)																	0	0	0
Forfeiture of restricted common stock (in shares)																	(0)	0	0
Forfeiture of restricted common stock															0	0	$ 0	$ (6)			0
Forfeiture of restricted common stock																				0
Purchases of common stock															0	0	$ (1)	$ (10)	$ (6,283)		(6,283)
Purchases of common stock (in shares)																	(11)	(98)
Purchases of common stock																				11
Foreign currency translation adjustment, net of taxes of $26															0	(3,776)	$ 0	$ 0	0	0	(3,776)
Unrealized holding gains on interest rate swap cash flow hedge, net of taxes of $0															0	340	0	0	0	0	340
Unrealized holding gains on marketable securities, net of taxes of $0															0	1	0	0	0	0	1
Stock-based compensation expense															0	0	0	0	0	804	804
Change in unfunded SERP liability, net of taxes of ($4)															0	15	0	0	0	0	15
Balance at Mar. 31, 2024															$ 322,508	$ (15,457)	$ 213	$ 1,061	$ (6,737)	$ 45,069	$ 346,657
Balance (in shares) at Mar. 31, 2024																	2,131	10,574