Note 4 - Earnings Per Share - Basic and Diluted Net Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		15 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2021
Net earnings	$ 5,064	$ 3,199
Undistributed earnings	4,208	2,355
Common Class A [Member]
Net earnings	821	522
Less dividends declared	129	128	$ 128
Undistributed earnings	$ 692	$ 394
Class A - basic and diluted (in shares)	2,145	2,145
Common shares - basic and diluted (in dollars per share)	$ 0.38	$ 0.24
Common Class B [Member]
Net earnings	$ 4,243	$ 2,677
Less dividends declared	727	716
Undistributed earnings	$ 3,516	$ 1,961
Class A - basic and diluted (in shares)	10,374	10,203
Common shares - basic and diluted (in dollars per share)	$ 0.41	$ 0.26