Nature of Business and Summary of Significant Accounting Policies (Narrative) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jun. 30, 2018
Significant Accounting Policies [Line Items]
Short-term time deposits	$ 460,000		$ 460,000
Intangible assets amortization expense	78,000	$ 93,000	235,000	$ 278,000
Estimated amortization expense-2019	313,000		313,000
Estimated amortization expense-2020	264,000		264,000
Estimated amortization expense-2021	223,000		223,000
Estimated amortization expense-2022	188,000		188,000
Estimated amortization expense-2023	159,000		$ 159,000
Weighted average amortization period for acquired intangible assets			9 years 4 months 24 days	10 years 4 months 24 days
Research and development costs	1,851,000	1,669,000	$ 5,358,000	$ 4,915,000
Antidilutive options outstanding excluded from diluted EPS computations			3,942	290
Stock-based compensation costs	0	5,000,000	$ 152,000	$ 141,000
Cost of Goods and Services Sold	14,414,000	13,308,000	42,389,000	38,629,000
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Advertising and promotion costs	190,000	171,000	1,275,000	1,274,000
Sales revenue, net [Member] | Shipping and Handling [Member]
Significant Accounting Policies [Line Items]
Cost of Goods and Services Sold	280,000	247,000	827,000	706,000
Cost of sales [Member]
Significant Accounting Policies [Line Items]
Research and development costs	1,851,000	1,669,000	5,358,000	4,915,000
Cost of sales [Member] | Shipping and Handling [Member]
Significant Accounting Policies [Line Items]
Cost of Goods and Services Sold	109,000	$ 105,000	313,000	$ 352,000
Allowance for doubtful accounts current [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	$ 117,000		$ 117,000		$ 195,000