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

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

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