Condensed Consolidating Statements of Income and Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Type of Revenue [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Net revenues	$ 457,786			$ 418,498			$ 1,290,985	$ 1,199,324
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Direct advertising expenses	$ 148,846			$ 140,699			$ 435,706	$ 419,776
General and administrative expenses	80,561			73,166			238,270	213,060
Corporate expenses	23,185			20,776			58,888	62,027
Depreciation and amortization	63,951			55,089			187,150	167,251
(Gain) loss on disposition of assets	(199)			407			(5,360)	7,265
Total Operating Expenses	316,344			290,137			914,654	869,379
Operating income	141,442			128,361			376,331	329,945
Income before income tax expense	103,287			96,668			262,644	217,508
Income tax expense (benefit)	3,578			2,612			(6,714)	7,969
Net income	99,709	$ 118,396	$ 51,253	94,056	$ 100,431	$ 15,052	269,358	209,539
Statements of Comprehensive Income
Net income	99,709	$ 118,396	$ 51,253	94,056	$ 100,431	$ 15,052	269,358	209,539
Comprehensive income	$ 99,535			$ 94,277			$ 269,730	$ 208,940
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Type of Revenue [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Net revenues	$ 457,786			$ 418,498			$ 1,290,985	$ 1,199,324
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Direct advertising expenses	$ 148,846			$ 140,699			$ 435,706	$ 419,776
General and administrative expenses	80,561			73,166			238,270	213,060
Corporate expenses	23,062			20,667			58,567	61,723
Depreciation and amortization	63,951			55,089			187,150	167,251
(Gain) loss on disposition of assets	(199)			407			(5,360)	7,265
Total Operating Expenses	316,221			290,028			914,333	869,075
Operating income	141,565			128,470			376,652	330,249
Interest expense (income), net	38,155			31,693			113,687	97,008
Other expenses								15,429
Income before income tax expense	103,410			96,777			262,965	217,812
Income tax expense (benefit)	3,578			2,612			(6,714)	7,969
Net income	99,832			94,165			269,679	209,843
Statements of Comprehensive Income
Net income	99,832			94,165			269,679	209,843
Total other comprehensive income (loss), net of tax	(174)			221			372	(599)
Comprehensive income	$ 99,658			$ 94,386			$ 270,051	$ 209,244
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Lamar Media [Member]
Type of Revenue [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Equity in (earnings) loss of subsidiaries	$ (136,714)			$ (126,015)			$ (379,424)	$ (322,592)
Interest expense (income), net	36,882			31,850			109,745	97,320
Other expenses								15,429
Income before income tax expense	99,832			94,165			269,679	209,843
Net income	99,832			94,165			269,679	209,843
Statements of Comprehensive Income
Net income	99,832			94,165			269,679	209,843
Comprehensive income	$ 99,832			$ 94,165			$ 269,679	$ 209,843
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Type of Revenue [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Net revenues	$ 446,838			$ 407,656			$ 1,258,493	$ 1,164,039
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Direct advertising expenses	$ 142,412			$ 134,863			$ 417,271	$ 400,703
General and administrative expenses	78,470			71,046			232,602	206,522
Corporate expenses	22,645			20,252			57,542	60,468
Depreciation and amortization	63,033			53,956			184,897	162,536
(Gain) loss on disposition of assets	(185)			559			(1,195)	(268)
Total Operating Expenses	306,375			280,676			891,117	829,961
Operating income	140,463			126,980			367,376	334,078
Interest expense (income), net	(7)			(8)			(94)	(18)
Income before income tax expense	140,470			126,988			367,470	334,096
Income tax expense (benefit)	3,255			2,167			(9,357)	5,708
Net income	137,215			124,821			376,827	328,388
Statements of Comprehensive Income
Net income	137,215			124,821			376,827	328,388
Comprehensive income	$ 137,215			$ 124,821			$ 376,827	$ 328,388
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Type of Revenue [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Net revenues	$ 11,539			$ 11,659			$ 34,563	$ 37,880
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Direct advertising expenses	$ 7,025			$ 6,522			$ 20,506	$ 21,042
General and administrative expenses	2,091			2,120			5,668	6,538
Corporate expenses	417			415			1,025	1,255
Depreciation and amortization	918			1,133			2,253	4,715
(Gain) loss on disposition of assets	(14)			(152)			(4,165)	7,533
Total Operating Expenses	10,437			10,038			25,287	41,083
Operating income	1,102			1,621			9,276	(3,203)
Interest expense (income), net	1,280			(18)			4,036	332
Income before income tax expense	(178)			1,639			5,240	(3,535)
Income tax expense (benefit)	323			445			2,643	2,261
Net income	(501)			1,194			2,597	(5,796)
Statements of Comprehensive Income
Net income	(501)			1,194			2,597	(5,796)
Total other comprehensive income (loss), net of tax	(174)			221			372	(599)
Comprehensive income	$ (675)			$ 1,415			$ 2,969	$ (6,395)
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Eliminations [Member]
Type of Revenue [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Net revenues	$ (591)			$ (817)			$ (2,071)	$ (2,595)
Operating expenses
Type of Cost, Good or Service [Extensible List]	us-gaap:AdvertisingMember			us-gaap:AdvertisingMember			us-gaap:AdvertisingMember	us-gaap:AdvertisingMember
Direct advertising expenses	$ (591)			$ (686)			$ (2,071)	$ (1,969)
Total Operating Expenses	(591)			(686)			(2,071)	(1,969)
Operating income				(131)				(626)
Equity in (earnings) loss of subsidiaries	136,714			126,015			379,424	322,592
Interest expense (income), net				(131)				(626)
Income before income tax expense	(136,714)			(126,015)			(379,424)	(322,592)
Net income	(136,714)			(126,015)			(379,424)	(322,592)
Statements of Comprehensive Income
Net income	(136,714)			(126,015)			(379,424)	(322,592)
Comprehensive income	$ (136,714)			$ (126,015)			$ (379,424)	$ (322,592)