Note 11 - Treasury Stock and Repurchase Program - Treasury Stock at Cost (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended
	Oct. 31, 2023	Sep. 30, 2023	Aug. 31, 2023	Oct. 31, 2023	Jul. 31, 2023	Oct. 31, 2022	Jul. 31, 2022
Balance, shares (in shares)			569,471	569,471	565,460
Balance, total average cost assigned			$ 14,859	$ 14,859	$ 14,671
Balance, average cost per share (in dollars per share)			$ 26.09	$ 26.09
Balance, aggregate purchase price remaining under the program	$ 1,396	$ 1,463	$ 1,526	$ 1,396	1,546
Purchases effected in open market, shares (in shares)	1,809	1,324	413
Purchases effected in open market, cost	$ 67	$ 63	$ 20	$ 150	$ 188	$ 1,100	$ 2,382
Purchases effected in open market, average cost (in dollars per share)	$ 37.33	$ 47.43	$ 48.47
Balance, shares (in shares)	573,017			573,017	569,471
Balance, total average cost assigned	$ 15,009			$ 15,009	$ 14,859
Balance, average cost per share (in dollars per share)	$ 26.19			$ 26.19	$ 26.09