Note 8 - Earnings Per Share - Shares Used to Calculate Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Weighted average number of shares used in computation of basic earnings per share: (in shares)	56,114	55,992	56,089	55,990
Additional shares from the assumed exercise of employee stock awards (in shares)	384	324	342	512
Weighted average number of shares used in computation of diluted earnings per share (in shares)	56,498	56,316	56,431	56,502