Note 7 - Goodwill and Other Intangible Assets (Details) - Goodwill (USD $) In Thousands, unless otherwise specified	9 Months Ended
Mar. 31, 2015	Jun. 30, 2014
Goodwill [Line Items]
Goodwill	$ 75,224us-gaap_GoodwillGross	$ 78,343us-gaap_GoodwillGross
Accumulated impairment Losses	(64,716)	(67,835)
Net Goodwill	10,508us-gaap_Goodwill	10,508us-gaap_Goodwill
Lighting Segment [Member]
Goodwill [Line Items]
Goodwill	34,913	34,913
Accumulated impairment Losses	(34,778)	(34,778)
Net Goodwill	135	135
Graphics Segment [Member]
Goodwill [Line Items]
Goodwill	28,690	28,690
Accumulated impairment Losses	(27,525)	(27,525)
Net Goodwill	1,165	1,165
Technology Segment [Member]
Goodwill [Line Items]
Goodwill	11,621	11,621
Accumulated impairment Losses	(2,413)	(2,413)
Net Goodwill	9,208	9,208
All Other Category [Member] \| LSI Saco [Member]
Goodwill [Line Items]
Goodwill	(3,119)
Accumulated impairment losses	3,119
All Other Category [Member]
Goodwill [Line Items]
Goodwill		3,119
Accumulated impairment Losses		(3,119)
LSI Saco [Member]
Goodwill [Line Items]
Goodwill	(3,119)
Accumulated impairment losses	$ 3,119

The amount accumulated impairment losses that was eliminated due to the sale of a subsidiary.

No definition available.

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

- Definition

The amount of goodwill before accumulated impairment losses that was eliminated due to the sale of a subsidiary.

+ References

No definition available.

+ Details

Name:	lyts_GoodwillSaleofSubsidiary
Namespace Prefix:	lyts_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a,h)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

+ Details

Name:	us-gaap_GoodwillImpairedAccumulatedImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_GoodwillLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=lyts_LSISacoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=lyts_AllOtherCategoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=lyts_GraphicsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=lyts_LightingSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=lyts_TechnologySegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: