Nature of Business and Summary of Significant Accounting Policies (Narrative) (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Significant Accounting Policies [Line Items]
Short-term time deposits	$ 460,000		$ 460,000		$ 460,000
Intangible assets amortization expense	79,000	$ 92,000	157,000	$ 185,000
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 7 months 6 days	10 years 7 months 6 days
Research and development costs	$ 1,762,000	$ 1,639,000	$ 3,507,000	$ 3,246,000
Antidilutive options outstanding excluded from diluted EPS computations	11,826	870	5,913	435
Stock-based compensation costs	$ 147,000	$ 103,000	$ 152,000	$ 136,000
Cost of Goods and Services Sold	14,158,000	12,633,000	27,975,000	25,321,000
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Advertising and promotion costs	435,000	462,000	1,085,000	1,103,000
Sales revenue, net [Member] | Shipping and Handling [Member]
Significant Accounting Policies [Line Items]
Cost of Goods and Services Sold	265,000	252,000	547,000	459,000
Cost of sales [Member]
Significant Accounting Policies [Line Items]
Research and development costs	1,762,000	1,639,000	3,507,000	3,246,000
Cost of sales [Member] | Shipping and Handling [Member]
Significant Accounting Policies [Line Items]
Cost of Goods and Services Sold	103,000	$ 125,000	204,000	$ 247,000
Allowance for doubtful accounts current [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	$ 182,000		$ 182,000		$ 195,000