Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Class A [Member]
Common stock, authorized (in shares)	105,000,000	105,000,000
Common stock, outstanding (in shares)	62,307,564	61,461,281
Treasury Stock, Common, Shares (in shares)	1,299,589	1,092,142
Common Class B [Member]
Common stock, authorized (in shares)	35,000,000	35,000,000
Common stock, outstanding (in shares)	16,695,873	16,364,158
Treasury Stock, Common, Shares (in shares)	1,750,566	1,731,157