Long-term Debt - Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Debt	$ 2,926,633	$ 3,004,532
Debt, Less current maturities	(122,879)	(232,595)
Debt, excluding current maturities	2,803,754	2,771,937
Deferred financing costs	40,117	24,414
Deferred financing costs, Less current maturities	(445)	(6,081)
Deferred financing costs, excluding current maturities	39,672	18,333
Debt, net of deferred financing costs	2,886,516	2,980,118
Debt, net of deferred financing costs, Less current maturities	(122,434)	(226,514)
Long-term debt, net of deferred financing costs	2,764,082	2,753,604
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	2,926,633	3,004,532
Debt, Less current maturities	(122,879)	(232,595)
Debt, excluding current maturities	2,803,754	2,771,937
Deferred financing costs	40,117	24,414
Deferred financing costs, Less current maturities	(445)	(6,081)
Deferred financing costs, excluding current maturities	39,672	18,333
Debt, net of deferred financing costs	2,886,516	2,980,118
Debt, net of deferred financing costs, Less current maturities	(122,434)	(226,514)
Long-term debt, net of deferred financing costs	2,764,082	2,753,604
Senior Credit Facility [Member]
Debt Instrument [Line Items]
Debt	598,466	1,127,069
Deferred financing costs	11,569	9,077
Debt, net of deferred financing costs	586,897	1,117,992
Senior Credit Facility [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	598,466	1,127,069
Deferred financing costs	11,569	9,077
Debt, net of deferred financing costs	586,897	1,117,992
Accounts Receivable Securitization Program [Member]
Debt Instrument [Line Items]
Debt	122,500	175,000
Deferred financing costs	445	846
Debt, net of deferred financing costs	122,055	174,154
Accounts Receivable Securitization Program [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	122,500	175,000
Deferred financing costs	445	846
Debt, net of deferred financing costs	122,055	174,154
5% Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Debt		535,000
Deferred financing costs		3,237
Debt, net of deferred financing costs		531,763
5% Senior Subordinated Notes [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt		535,000
Deferred financing costs		3,237
Debt, net of deferred financing costs		531,763
5 3/8% Senior Notes [Member]
Debt Instrument [Line Items]
Debt		510,000
Deferred financing costs		3,502
Debt, net of deferred financing costs		506,498
5 3/8% Senior Notes [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt		510,000
Deferred financing costs		3,502
Debt, net of deferred financing costs		506,498
3 3/4% Senior Notes [Member]
Debt Instrument [Line Items]
Debt	600,000
Deferred financing costs	8,031
Debt, net of deferred financing costs	591,969
3 3/4% Senior Notes [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	600,000
Deferred financing costs	8,031
Debt, net of deferred financing costs	591,969
4% Senior Notes [Member]
Debt Instrument [Line Items]
Debt	549,280
Deferred financing costs	7,911
Debt, net of deferred financing costs	541,369
4 7/8% Senior Notes [Member]
Debt Instrument [Line Items]
Debt	400,000
Deferred financing costs	5,586
Debt, net of deferred financing costs	394,414
4 7/8% Senior Notes [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	400,000
Deferred financing costs	5,586
Debt, net of deferred financing costs	394,414
Other Notes with Various Rates and Terms [Member]
Debt Instrument [Line Items]
Debt	2,756	3,118
Debt, net of deferred financing costs	2,756	3,118
Other Notes with Various Rates and Terms [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	2,756	3,118
Debt, net of deferred financing costs	2,756	3,118
5 3/4% Senior Notes [Member]
Debt Instrument [Line Items]
Debt	653,631	654,345
Deferred financing costs	6,575	7,752
Debt, net of deferred financing costs	647,056	646,593
5 3/4% Senior Notes [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	653,631	654,345
Deferred financing costs	6,575	7,752
Debt, net of deferred financing costs	647,056	$ 646,593
4% Senior Notes [Member] \| LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Debt Instrument [Line Items]
Debt	549,280
Deferred financing costs	7,911
Debt, net of deferred financing costs	$ 541,369

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Long term debt, net of deferred financing costs.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt issuance costs classified as current. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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