General and Summary of Significant Accounting Policies Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
NET INCOME PER SHARE
Net Income	$ 103,135	$ 86,870	$ 101,035
Weighted average number of common shares outstanding (basic)	21,206,000	20,907,000	20,629,000
Weighted Average Number Diluted Shares Outstanding Adjustment	575,000	684,000	916,000
Weighted Average common and common equivalent shares outstandding (diluted)	21,781,000	21,591,000	21,545,000
Basic	$ 4.86	$ 4.16	$ 4.90
Diluted	$ 4.74	$ 4.02	$ 4.69
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	12,354	12,083	10,760