Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Total current assets	$ 365,898	$ 420,519
Net property, plant and equipment	1,193,313	1,214,138
Other assets	54,349	42,886
Total assets	4,124,620	4,214,345
Current liabilities:
Current maturities of long-term debt	26,728	17,664
Total current liabilities	255,984	325,994
Long-term debt, net of deferred financing costs	2,519,153	2,539,026
Total liabilities	3,027,661	3,110,852
Stockholders’ equity	1,096,959	1,103,493
Total liabilities and stockholders’ equity	4,124,620	4,214,345
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
ASSETS
Total current assets	365,398	420,019
Net property, plant and equipment	1,193,313	1,214,138
Intangibles and goodwill, net	2,500,441	2,526,182
Other assets	48,683	37,603
Total assets	4,107,835	4,197,942
Current liabilities:
Current maturities of long-term debt	26,728	17,664
Other current liabilities	224,671	304,322
Total current liabilities	251,399	321,986
Long-term debt, net of deferred financing costs	2,519,153	2,539,026
Other noncurrent liabilities	252,524	245,832
Total liabilities	3,023,076	3,106,844
Stockholders’ equity	1,084,759	1,091,098
Total liabilities and stockholders’ equity	4,107,835	4,197,942
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Lamar Media [Member]
ASSETS
Total current assets	6,180	87,167
Other assets	3,674,150	3,707,352
Total assets	3,680,330	3,794,519
Current liabilities:
Current maturities of long-term debt	26,694	17,664
Other current liabilities	22,050	120,500
Total current liabilities	48,744	138,164
Long-term debt, net of deferred financing costs	2,519,076	2,539,026
Other noncurrent liabilities	27,751	26,231
Total liabilities	2,595,571	2,703,421
Stockholders’ equity	1,084,759	1,091,098
Total liabilities and stockholders’ equity	3,680,330	3,794,519
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
ASSETS
Total current assets	342,780	293,536
Net property, plant and equipment	1,187,773	1,193,705
Intangibles and goodwill, net	2,480,597	2,495,370
Other assets	11,407	10,571
Total assets	4,022,557	3,993,182
Current liabilities:
Current maturities of long-term debt	34
Other current liabilities	183,809	164,393
Total current liabilities	183,843	164,393
Long-term debt, net of deferred financing costs	77
Other noncurrent liabilities	223,199	218,900
Total liabilities	407,119	383,293
Stockholders’ equity	3,615,438	3,609,889
Total liabilities and stockholders’ equity	4,022,557	3,993,182
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Total current assets	16,438	39,316
Net property, plant and equipment	5,540	20,433
Intangibles and goodwill, net	19,844	30,812
Other assets	9,498	7
Total assets	51,320	90,568
Current liabilities:
Other current liabilities	18,812	19,429
Total current liabilities	18,812	19,429
Other noncurrent liabilities	29,529	61,587
Total liabilities	48,341	81,016
Stockholders’ equity	2,979	9,552
Total liabilities and stockholders’ equity	51,320	90,568
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Eliminations [Member]
ASSETS
Other assets	(3,646,372)	(3,680,327)
Total assets	(3,646,372)	(3,680,327)
Current liabilities:
Other noncurrent liabilities	(27,955)	(60,886)
Total liabilities	(27,955)	(60,886)
Stockholders’ equity	(3,618,417)	(3,619,441)
Total liabilities and stockholders’ equity	$ (3,646,372)	$ (3,680,327)