Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - 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] 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] 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]	Additional Paid-in Capital [Member]	Total
Balance at Dec. 31, 2020													$ 166,491	$ (18,063)	$ 214	$ 1,021	$ 36,136	$ 185,799
Net earnings						$ 522						$ 2,677	3,199	0	0	0	0	3,199
Cash dividends declared on common stock						(128)	$ (716)	$ 0	$ 0	$ 0	$ 0	(716)
Forfeiture of restricted common stock													0	0	0	(1)		0
Forfeiture of restricted common stock, APIC																	1
Foreign currency translation adjustment, net of taxes													0	(2,529)	0	0	0	(2,529)
Stock-based compensation expense													0	0	0	0	600	600
Change in unfunded SERP liability, net of taxes													0	99	0	0	0	99
Unrealized gains (losses) on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented													0	(1)	0	0	0	(1)
Balance at Mar. 31, 2021													168,846	(20,494)	214	1,020	36,737	186,323
Balance at Dec. 31, 2021													187,935	(18,863)	214	1,038	38,419	208,743
Net earnings						821						4,243	5,064	0	0	0	0	5,064
Cash dividends declared on common stock	$ (129)	$ 0	$ 0	$ 0	$ 0	$ (129)	$ (727)	$ 0	$ 0	$ 0	$ 0	$ (727)
Forfeiture of restricted common stock													0	0	0	(1)		0
Forfeiture of restricted common stock, APIC																	1
Foreign currency translation adjustment, net of taxes													0	(1,216)	0	0	0	(1,216)
Unrealized gains on interest rate swap cash flow hedge													0	2,984	0	0	0	2,984
Stock-based compensation expense													0	0	0	0	576	576
Change in unfunded SERP liability, net of taxes													0	61	0	0	0	61
Unrealized gains (losses) on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented																		2,984
Balance at Mar. 31, 2022													$ 192,143	$ (17,034)	$ 214	$ 1,037	$ 38,996	$ 215,356