Note I - Treasury Stock (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Mar. 28, 2017	May 11, 2015	Feb. 06, 2015	Jun. 02, 2011
Stock Repurchase Program, Authorized Amount					$ 7,000,000	$ 5,000,000	$ 3,000,000	$ 2,000,000
Shares Paid for Tax Withholding for Share Based Compensation	35,203	32,325	43,201	38,729
Shares Paid for Tax Withholding for Share-based Compensation, Average Cost Per Share	$ 11.90	$ 8.75	$ 11.69	$ 9.47
Payments Related to Tax Withholding for Share-based Compensation	$ 419,000	$ 283,000	$ 505,000	$ 367,000
Excluding Restricted Stock Purchased [Member]
Treasury Stock, Shares, Acquired	0		0	39,547
Treasury Stock Acquired, Average Cost Per Share				$ 8.74
Treasury Stock, Value, Acquired, Cost Method				$ 345,000
2015 Increase [Member]
Stock Repurchase Program, Authorized Amount						$ 2,000,000	$ 1,000,000
2017 Increase [Member]
Stock Repurchase Program, Authorized Amount					$ 2,000,000