Note 15 - Restructuring Costs (Details Textual) - USD ($)	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Inventory Write-down	$ 2,605,000	$ 2,088,000	$ 1,726,000
Gain (Loss) on Disposition of Property Plant Equipment, Total		1,361,000		$ 343,000
Restructuring Charges, Total	0
Closure of Kansas City Facility [Member]
Restructuring and Related Cost, Expected Cost, Total		944,000
Inventory Write-down		485,000
Gain (Loss) on Disposition of Property Plant Equipment, Total		1,361,000
Consolidation of Beaverton, Oregon Facility into Other LSI Facilities [Member]
Restructuring Charges, Total	0	377,000
Consolidation of Woonsocket, Rhode Island Manufacturing Operation into Its North Canton, Ohio Operation [Member]
Restructuring and Related Cost, Expected Cost, Total		452,000
Restructuring Charges, Total	$ 0
Closure of Kansas City Facility and Consolidation of Beaverton, Oregon Facility Into Other LSI Facilities [Member]
Inventory Write-down		485,000
Closure of Kansas City Facility and Consolidation of Beaverton, Oregon Facility Into Other LSI Facilities [Member] | Machinery and Equipment at the Kansas City and Beaverton Facilities [Member]
Impairment of Long-Lived Assets Held-for-use		$ 354,000