Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Total current assets	$ 316,553			$ 363,669
Net property, plant and equipment	1,340,769			1,295,048
Operating lease right of use assets	1,296,312
Other assets	55,764			51,085
Total assets	5,931,736			4,544,641
Current liabilities:
Current maturities of long-term debt	218,105			204,120
Total current liabilities	620,173			455,035
Long-term debt, net of deferred financing costs	2,835,696			2,684,568
Total liabilities	4,763,915			3,412,857
Stockholders’ equity	1,167,821	$ 1,139,295	$ 1,109,578	1,131,784	$ 1,096,959	$ 1,073,520	$ 1,040,199	$ 1,103,493
Total liabilities and stockholders’ equity	5,931,736			4,544,641
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
ASSETS
Total current assets	316,053			363,169
Net property, plant and equipment	1,340,769			1,295,048
Operating lease right of use assets	1,296,312
Intangibles and goodwill, net	2,911,719			2,824,219
Other assets	50,147			45,450
Total assets	5,915,000			4,527,886
Current liabilities:
Current maturities of long-term debt	218,105			204,120
Other current liabilities	396,307			245,748
Total current liabilities	614,412			449,868
Long-term debt, net of deferred financing costs	2,835,696			2,684,568
Other noncurrent liabilities	1,308,046			273,254
Total liabilities	4,758,154			3,407,690
Stockholders’ equity	1,156,846			1,120,196
Total liabilities and stockholders’ equity	5,915,000			4,527,886
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Lamar Media [Member]
ASSETS
Total current assets	13,918			4,653
Other assets	4,243,934			4,056,288
Total assets	4,257,852			4,060,941
Current liabilities:
Current maturities of long-term debt	43,071			29,086
Other current liabilities	17,898			27,067
Total current liabilities	60,969			56,153
Long-term debt, net of deferred financing costs	2,835,653			2,684,500
Other noncurrent liabilities	204,384			200,092
Total liabilities	3,101,006			2,940,745
Stockholders’ equity	1,156,846			1,120,196
Total liabilities and stockholders’ equity	4,257,852			4,060,941
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
ASSETS
Total current assets	49,344			121,549
Net property, plant and equipment	1,333,395			1,289,348
Operating lease right of use assets	1,268,434
Intangibles and goodwill, net	2,893,303			2,804,915
Other assets	249,595			230,504
Total assets	5,794,071			4,446,316
Current liabilities:
Current maturities of long-term debt	34			34
Other current liabilities	354,287			204,103
Total current liabilities	354,321			204,137
Long-term debt, net of deferred financing costs	43			68
Other noncurrent liabilities	1,256,732			246,312
Total liabilities	1,611,096			450,517
Stockholders’ equity	4,182,975			3,995,799
Total liabilities and stockholders’ equity	5,794,071			4,446,316
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
ASSETS
Total current assets	252,791			236,967
Net property, plant and equipment	7,374			5,700
Operating lease right of use assets	27,878
Intangibles and goodwill, net	18,416			19,304
Other assets	184,805			184,247
Total assets	491,264			446,218
Current liabilities:
Current maturities of long-term debt	175,000			175,000
Other current liabilities	24,122			14,578
Total current liabilities	199,122			189,578
Other noncurrent liabilities	284,368			251,835
Total liabilities	483,490			441,413
Stockholders’ equity	7,774			4,805
Total liabilities and stockholders’ equity	491,264			446,218
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] | Eliminations [Member]
ASSETS
Other assets	(4,628,187)			(4,425,589)
Total assets	(4,628,187)			(4,425,589)
Current liabilities:
Other noncurrent liabilities	(437,438)			(424,985)
Total liabilities	(437,438)			(424,985)
Stockholders’ equity	(4,190,749)			(4,000,604)
Total liabilities and stockholders’ equity	$ (4,628,187)			$ (4,425,589)