Note 9 - Cash Dividends (Details Textual) - USD ($)	1 Months Ended	9 Months Ended
Apr. 29, 2019	Mar. 31, 2019	Mar. 31, 2018
Payments of Dividends, Total		$ 3,882,000	$ 3,845,000
Dividends Accrued		$ 40,798	$ 44,946
Subsequent Event [Member]
Quarterly Indicated Per Share Dividend Rate	$ 0.05
Annual Indicated per Share Dividend Rate	$ 0.20
Dividends Payable, Date to be Paid	May 14, 2019
Dividends Payable, Date of Record	May 06, 2019

The indicated per share dividend rate for a specific fiscal year.

No definition available.

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Namespace Prefix:	lyts_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Dividends declared but unpaid on equity securities issued by the entity during the period.

+ References

No definition available.

+ Details

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

- Definition

The indicated per share quarterly cash dividend rate.

+ References

No definition available.

+ Details

Name:	lyts_QuarterlyIndicatedPerShareDividendRate
Namespace Prefix:	lyts_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Data Type:	na
Balance Type:
Period Type: