Divestiture of assets.

No definition available.

Name:	lamr_DivestitureOfAssetsLineItems
Namespace Prefix:	lamr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Divestiture of businesses non cash consideration notes received.

+ References

No definition available.

+ Details

Name:	lamr_DivestitureOfBusinessesNonCashConsiderationNotesReceived
Namespace Prefix:	lamr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromDivestitureOfBusinesses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	srt_StatementGeographicalAxis=country_PR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Divestiture of Assets - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 16, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Divestiture Of Assets [Line Items]
Loss (gain) on disposition of assets		$ 407	$ (2,734)	$ 7,265	$ (4,377)
Puerto Rico [Member]
Divestiture Of Assets [Line Items]
Non-cash consideration consisting of note receivable	$ 9,500
Cash on sale of assets	$ 3,000
Loss (gain) on disposition of assets				$ 7,533