Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Total current assets	$ 380,570	$ 310,169
Net property, plant and equipment	1,281,849	1,349,115
Operating lease right of use assets	1,222,013	1,320,779
Other assets	60,565	56,574
Total assets	5,791,441	5,941,155
Current liabilities:
Current maturities of long-term debt	122,434	226,514
Current operating lease liabilities	195,439	196,841
Total current liabilities	547,872	672,808
Long-term debt	2,764,082	2,753,604
Operating lease liabilities	993,776	1,068,181
Total liabilities	4,588,673	4,760,849
Stockholders’ equity	1,202,768	1,180,306	$ 1,131,784	$ 1,103,493
Total liabilities and stockholders’ equity	5,791,441	5,941,155
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
ASSETS
Total current assets	380,070	309,669
Net property, plant and equipment	1,281,849	1,349,115
Operating lease right of use assets	1,222,013	1,320,779
Intangibles and goodwill, net	2,816,155	2,893,899
Other assets	74,620	50,959
Total assets	5,774,707	5,924,421
Current liabilities:
Current maturities of long-term debt	122,434	226,514
Current operating lease liabilities	195,439	196,841
Other current liabilities	223,189	243,494
Total current liabilities	541,062	666,849
Long-term debt	2,764,082	2,753,604
Operating lease liabilities	993,776	1,068,181
Other noncurrent liabilities	282,943	266,256
Total liabilities	4,581,863	4,754,890
Stockholders’ equity	1,192,844	1,169,531
Total liabilities and stockholders’ equity	5,774,707	5,924,421
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Lamar Media [Member]
ASSETS
Total current assets	110,678	13,859
Other assets	3,912,122	4,193,629
Total assets	4,022,800	4,207,488
Current liabilities:
Current maturities of long-term debt		51,480
Other current liabilities	33,583	26,960
Total current liabilities	33,583	78,440
Long-term debt	2,761,705	2,753,570
Other noncurrent liabilities	34,668	205,947
Total liabilities	2,829,956	3,037,957
Stockholders’ equity	1,192,844	1,169,531
Total liabilities and stockholders’ equity	4,022,800	4,207,488
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
ASSETS
Total current assets	19,471	53,756
Net property, plant and equipment	1,268,765	1,340,675
Operating lease right of use assets	1,200,115	1,293,674
Intangibles and goodwill, net	2,798,343	2,875,644
Other assets	258,433	229,905
Total assets	5,545,127	5,793,654
Current liabilities:
Current maturities of long-term debt	379	34
Current operating lease liabilities	188,712	189,071
Other current liabilities	170,320	196,689
Total current liabilities	359,411	385,794
Long-term debt	2,377	34
Operating lease liabilities	979,785	1,049,220
Other noncurrent liabilities	245,891	231,416
Total liabilities	1,587,464	1,666,464
Stockholders’ equity	3,957,663	4,127,190
Total liabilities and stockholders’ equity	5,545,127	5,793,654
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Total current assets	249,921	242,054
Net property, plant and equipment	13,084	8,440
Operating lease right of use assets	21,898	27,105
Intangibles and goodwill, net	17,812	18,255
Other assets	132,448	184,805
Total assets	435,163	480,659
Current liabilities:
Current maturities of long-term debt	122,055	175,000
Current operating lease liabilities	6,727	7,770
Other current liabilities	19,286	19,845
Total current liabilities	148,068	202,615
Operating lease liabilities	13,991	18,961
Other noncurrent liabilities	266,968	250,859
Total liabilities	429,027	472,435
Stockholders’ equity	6,136	8,224
Total liabilities and stockholders’ equity	435,163	480,659
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Eliminations [Member]
ASSETS
Other assets	(4,228,383)	(4,557,380)
Total assets	(4,228,383)	(4,557,380)
Current liabilities:
Other noncurrent liabilities	(264,584)	(421,966)
Total liabilities	(264,584)	(421,966)
Stockholders’ equity	(3,963,799)	(4,135,414)
Total liabilities and stockholders’ equity	$ (4,228,383)	$ (4,557,380)