Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
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)	41,715,105	42,808,333
Treasury Stock, Common, Shares (in shares)	2,635,163	979,978
Common Class B [Member]
Common stock, authorized (in shares)	35,000,000	35,000,000
Common stock, outstanding (in shares)	12,179,225	12,266,309
Treasury Stock, Common, Shares (in shares)	1,297,059	927,330