Nature of Business and Summary of Significant Accounting Policies (Narrative) (Detail) - USD ($)	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017
Significant Accounting Policies [Line Items]
Carrying amount of long-term debt, including current portion	$ 3,500,000
Short-term time deposits	460,000		$ 460,000
Intangible assets amortization expense	93,000	$ 110,000
Estimated amortization expense-2018	371,000
Estimated amortization expense-2019	313,000
Estimated amortization expense-2020	264,000
Estimated amortization expense-2021	223,000
Estimated amortization expense-2022	$ 188,000
Weighted average amortization period for acquired intangible assets	10 years 10 months 24 days	11 years 10 months 24 days
Stock-based compensation costs	$ 33,000	$ 33,000
Sales Returns And Allowances Percentage	8.00%	9.00%
Stock-based compensation costs, effect on EPS	$ 0.00	$ 0.00
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Advertising and promotion costs	$ 641,000	$ 674,000
Sales revenue, net [Member]
Significant Accounting Policies [Line Items]
Shipping and handling revenue	207,000	216,000
Cost of sales [Member]
Significant Accounting Policies [Line Items]
Research and development costs	1,627,000	1,628,000
Shipping and handling expense	122,000	$ 139,000
Allowance for doubtful accounts current [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	175,000		155,000
Returns and other allowances [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	$ 1,170,000		$ 1,250,000