XML 111 R98.htm IDEA: XBRL DOCUMENT v3.22.4
Note 11 - Stock-based Compensation - Summary of Stock Option Activity (Details) - $ / shares
 12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) 0 0 0
Exercised (in shares) (1,355) (2,000) (753)
Mercantile Plans [Member]      
Outstanding at beginning of year (in shares) 7,700 9,700 10,700
Outstanding at beginning of year, weighted average exercise price (in dollars per share) $ 34.89 $ 32.83 $ 30.25
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) 0 0 0
Exercised (in shares) (2,700) (2,000) (1,000)
Exercised, weighted average exercise price (in dollars per share) $ 32.42 $ 24.91 $ 5.19
Forfeited or expired (in shares) 0 0 0
Outstanding at end of year (in shares) 5,000 7,700 9,700
Outstanding at end of year, weighted average exercise price (in dollars per share) $ 36.22 $ 34.89 $ 32.83
Options exercisable at year-end (in shares) 5,000 7,700 9,700
Options exercisable at year-end, weighted average exercise price (in dollars per share) $ 36.22 $ 34.89 $ 32.83