Revenue from Contracts with Customers (Summary of Cumulative Effect of Changes to Unaudited Consolidated Statement of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Net Sales	$ 76,822	$ 84,693	$ 77,947
Cost of Sales	49,630	52,693	50,178
Gross Profit	27,192	32,000	27,769
Operating Expenses
Selling, general and administrative	18,980	18,469
Engineering, research and development	8,040	7,980
Severance, impairment and other charges	6,930	603
Total operating expenses	33,950	27,052	25,950
Operating (Loss) Income	(6,758)	4,948	1,819
Other Income and (Expenses)
Interest expense, net	(252)	(181)
Foreign currency loss, net	(90)	(397)
Other income (expense), net	97	119
Total other income and (expense)	(245)	(459)	(557)
(Loss) Income Before Income Taxes	(7,003)	4,489	1,262
Income Tax (Expense) Benefit	212	(516)	(1,177)
Net (Loss) Income	(6,791)	$ 3,973	$ 85
ASC 606 Adjustments [Member] | ASC 606 [Member]
Net Sales	(4,043)
Cost of Sales	(2,506)
Gross Profit	(1,537)
Operating Expenses
Selling, general and administrative	2
Total operating expenses	2
Operating (Loss) Income	(1,539)
Other Income and (Expenses)
(Loss) Income Before Income Taxes	(1,539)
Income Tax (Expense) Benefit	(157)
Net (Loss) Income	(1,696)
Balances Without Adoption of ASC 606 [Member] | ASC 606 [Member]
Net Sales	72,779
Cost of Sales	47,124
Gross Profit	25,655
Operating Expenses
Selling, general and administrative	18,982
Engineering, research and development	8,040
Severance, impairment and other charges	6,930
Total operating expenses	33,952
Operating (Loss) Income	(8,297)
Other Income and (Expenses)
Interest expense, net	(252)
Foreign currency loss, net	(90)
Other income (expense), net	97
Total other income and (expense)	(245)
(Loss) Income Before Income Taxes	(8,542)
Income Tax (Expense) Benefit	55
Net (Loss) Income	$ (8,487)