Consolidated Balance Sheet (Current Period Unaudited) (Parentheticals) - $ / shares $ / shares in Thousands	Sep. 30, 2020	Dec. 31, 2019
Preferred stock, par value (in dollars per share)	$ 0
Preferred stock, authorized shares (in shares)	1,000,000	1,000,000
Preferred stock, issued shares (in shares)	0	0
Preferred stock, outstanding shares (in shares)	0	0
Common Class A [Member]
Class of common stock, par value (in dollars per share)	$ 0	$ 0
Class of common stock, shares authorized (in shares)	10,000,000	10,000,000
Class of common stock, shares issued (in shares)	2,591,837	2,576,837
Treasury shares, issued (in shares)	39,305	37,208
Common Class B [Member]
Class of common stock, par value (in dollars per share)	$ 0	$ 0
Class of common stock, shares authorized (in shares)	2,500,000	2,500,000
Class of common stock, shares issued (in shares)	954,283	954,283
Treasury shares, issued (in shares)	182,435	182,435