Note 11 - Treasury Stock and Repurchase Program - Treasury Stock at Cost (Details) - USD ($)	1 Months Ended			3 Months Ended
	Jan. 31, 2024	Dec. 31, 2023	Nov. 30, 2023	Oct. 31, 2023	Jul. 31, 2023	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022
Balance, shares (in shares)			573,017		565,460
Balance, total average cost assigned			$ 15,009,000		$ 14,671,000
Balance, average cost per share (in dollars per share)			$ 26.19
Balance, aggregate purchase price remaining under the program	$ 1,396,000	$ 1,396,000	$ 1,396,000	$ 1,396,000
Purchases effected in open market, shares (in shares)	0	0	0
Purchases effected in open market, cost	$ 0	$ 0	$ 0	$ 150,000	$ 188,000	$ 1,005,000	$ 1,100,000	$ 2,382,000
Purchases effected in open market, average cost (in dollars per share)	$ 0	$ 0	$ 0
Balance, shares (in shares)	573,017			573,017
Balance, total average cost assigned	$ 15,009,000			$ 15,009,000
Balance, average cost per share (in dollars per share)	$ 26.19			$ 26.19