Note 15 - Severance Costs (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2021	Jun. 30, 2020
Severance Expense	$ 41	$ 344
Maximum [Member]
Severance Expense	$ 100

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

No definition available.

Name:	lyts_SeveranceExpense
Namespace Prefix:	lyts_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration