Consolidated Statements of Stockholders' Equity (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Common Class A [Member]
Dividends declared (in dollars per share)	$ 0.24	$ 0.24
Common Class B [Member]
Dividends declared (in dollars per share)	$ 0.28	$ 0.28
Foreign currency translation adjustment, tax expense	$ 8	$ 9
Change in unfunded SERP liability, tax	$ 738	$ (422)

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

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