Note D - Other Comprehensive Loss (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Revenue from Contract with Customer, Including Assessed Tax	$ 35,455,000	$ 31,815,000	$ 108,030,000	$ 93,224,000
Interest Income (Expense), Net, Total	(11,000)	(6,000)	(23,000)	(6,000)
Other Nonoperating Income (Expense), Total	(10,000)	(5,000)	(1,000)	(18,000)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Revenue from Contract with Customer, Including Assessed Tax	450,000	974,000	619,000	1,800,000
Interest Income (Expense), Net, Total	368,000	$ 206,000	1,300,000	$ 691,000
Other Nonoperating Income (Expense), Total	$ 122,000		$ 122,000