Nature of Business and Summary of Significant Accounting Policies (Narrative) (Detail) - USD ($)	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
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	441,000	$ 529,000	$ 667,000
Estimated amortization expense-2017	371,000
Estimated amortization expense-2018	313,000
Estimated amortization expense-2019	264,000
Estimated amortization expense-2020	223,000
Estimated amortization expense-2021	$ 188,000
Weighted average amortization period for acquired intangible assets	11 years 1 month 6 days	12 years 1 month 6 days
Antidilutive options outstanding excluded from diluted EPS computations	0	127,404	255,688
Stock-based compensation costs	$ 102,000	$ 103,000	$ 101,000
Sales Returns And Allowances Percentage	7.00%	7.00%	8.00%
Stock-based compensation costs, effect on EPS	$ 0.01	$ 0.01	$ 0.01
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Advertising and promotion costs	$ 2,444,000	$ 2,144,000	$ 1,671,000
Sales revenue, net [Member]
Significant Accounting Policies [Line Items]
Shipping and handling revenue	947,000	918,000	945,000
Cost of sales [Member]
Significant Accounting Policies [Line Items]
Research and development costs	6,723,000	6,169,000	5,382,000
Shipping and handling expense	461,000	492,000	$ 515,000
Allowance for doubtful accounts current [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	155,000	145,000
Returns and other allowances [Member]
Significant Accounting Policies [Line Items]
Valuation allowances and reserves, balance	$ 1,250,000	$ 1,255,000