Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Common Class A [Member]
Dividends declared (in dollars per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06
Common Class B [Member]
Dividends declared (in dollars per share)	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07
Foreign currency translation adjustment, tax expense	$ (13)	$ (105)	$ 9	$ (40)	$ (31)	$ (12)
Unrealized losses on interest rate swap cash flow hedge, tax	0		0	0
Unrealized loss on marketable securities arising during the period, tax	0		0	0
Change in unfunded SERP liability, tax	$ (4)	$ (4)	$ (4)	$ (18)	$ (17)	$ (17)

Aggregate dividends declared during the period for each share of common stock outstanding.

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Amount, after reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness, attributable to parent.

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