Summary of Significant Accounting Policies - Narrative (Details) shares in Millions	12 Months Ended
	Jun. 30, 2020 USD ($) Segment lease shares	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($) shares	Jun. 30, 2017 USD ($)
Summary of Significant Accounting Policies Additional Information [Abstract]
Recorded bad debt expense	$ 0	$ 0	$ 0
Inventory valuation reserves	200,000	200,000
Impairment of intangible assets	0	0
Research and development	$ 900,000	$ 1,100,000	$ 1,200,000
Number of finance leases | lease	0
Number of antidilutive securities (in shares) | shares	0.1	0.2	0.4
Number of geographic segments | Segment	2
Right-of-use assets	$ 956,000	$ 0
Lease liabilities	1,184,000	0
Stockholders' equity attributable to parent	$ 33,254,000	27,707,000	$ 21,944,000	$ 14,527,000
Accounting standards update	us-gaap:AccountingStandardsUpdate201602Member
Cumulative effect of adoption of accounting principle
Summary of Significant Accounting Policies Additional Information [Abstract]
Right-of-use assets		3,300,000
Lease liabilities		3,900,000
Stockholders' equity attributable to parent		$ 508,000	$ (3,000)
Cash Accounts Held Primarily At Financial Institution
Summary of Significant Accounting Policies Additional Information [Abstract]
Concentration of credit risk	$ 17,800,000
Cash Accounts Held at Other Financial Institutions
Summary of Significant Accounting Policies Additional Information [Abstract]
Concentration of credit risk	$ 4,300,000