Condensed Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Cash flows from investing activities:
Acquisitions	$ (16,165)	$ (28,101)
Capital expenditures	(52,473)	(47,836)
Proceeds from disposition of assets and investments	3,407	2,566
Proceeds received from property insurance claims	3,804
Decrease in notes receivable	5	11
Cash flows from financing activities:
Proceeds received from revolving credit facility	190,000	182,000
Payment on revolving credit facility	(270,000)	(334,000)
Principal payments on long term debt	(12,911)	(5,625)
Proceeds received from senior credit facility term loans	599,250	450,000
Redemption of senior subordinated notes	(509,790)
Debt issuance costs	(6,349)	(4,899)
Distributions to non-controlling interest	(241)	(310)
Payment on senior credit facility term loans		(247,500)
Effect of exchange rate changes in cash and cash equivalents	(683)	798
Net (decrease) increase in cash and cash equivalents	(95,883)	7,354
Cash and cash equivalents at beginning of period	115,471	35,530
Cash and cash equivalents at end of period	19,588	42,884
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	202,241	173,560
Cash flows from investing activities:
Acquisitions	(16,165)	(28,101)
Capital expenditures	(52,473)	(47,836)
Proceeds from disposition of assets and investments	3,407	2,566
Proceeds received from property insurance claims	3,804
Decrease in notes receivable	5	11
Net cash provided by (used in) investing activities	(61,422)	(73,360)
Cash flows from financing activities:
Proceeds received from revolving credit facility	190,000	182,000
Payment on revolving credit facility	(270,000)	(334,000)
Principal payments on long term debt	(12,911)	(5,625)
Proceeds received from senior credit facility term loans	599,250	450,000
Redemption of senior subordinated notes	(509,790)
Debt issuance costs	(6,349)	(4,899)
Distributions to non-controlling interest	(241)	(310)
Dividends (to) from parent	(264,970)	(171,517)
Contributions from (to) parent	38,992	38,207
Net cash (used in) provided by financing activities	(236,019)	(93,644)
Payment on senior credit facility term loans		(247,500)
Effect of exchange rate changes in cash and cash equivalents	(683)	798
Net (decrease) increase in cash and cash equivalents	(95,883)	7,354
Cash and cash equivalents at beginning of period	114,971	35,030
Cash and cash equivalents at end of period	19,088	42,384
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] \| Reportable Legal Entities [Member] \| Lamar Media [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	146,324	127,087
Cash flows from investing activities:
Investment in subsidiaries	(16,165)	(28,101)
Decrease (increase) in intercompany notes receivable	28,618	(3,594)
Decrease in notes receivable	5	11
Net cash provided by (used in) investing activities	12,458	(31,684)
Cash flows from financing activities:
Proceeds received from revolving credit facility	190,000	182,000
Payment on revolving credit facility	(270,000)	(334,000)
Principal payments on long term debt	(12,897)	(5,625)
Proceeds received from senior credit facility term loans	599,250	450,000
Redemption of senior subordinated notes	(509,790)
Debt issuance costs	(6,349)	(4,899)
Dividends (to) from parent	(264,970)	(171,517)
Contributions from (to) parent	38,992	38,207
Net cash (used in) provided by financing activities	(235,764)	(93,334)
Payment on senior credit facility term loans		(247,500)
Net (decrease) increase in cash and cash equivalents	(76,982)	2,069
Cash and cash equivalents at beginning of period	86,546	12,762
Cash and cash equivalents at end of period	9,564	14,831
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] \| Reportable Legal Entities [Member] \| Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	268,161	230,322
Cash flows from investing activities:
Acquisitions	(16,165)	(28,101)
Capital expenditures	(48,506)	(43,858)
Proceeds from disposition of assets and investments		2,566
Net cash provided by (used in) investing activities	(64,671)	(69,393)
Cash flows from financing activities:
Principal payments on long term debt	(14)
Dividends (to) from parent	(220,034)	(187,751)
Contributions from (to) parent	16,165	28,101
Net cash (used in) provided by financing activities	(203,883)	(159,650)
Net (decrease) increase in cash and cash equivalents	(393)	1,279
Cash and cash equivalents at beginning of period	1,625	1,201
Cash and cash equivalents at end of period	1,232	2,480
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] \| Reportable Legal Entities [Member] \| Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	7,790	3,902
Cash flows from investing activities:
Capital expenditures	(3,967)	(3,978)
Proceeds from disposition of assets and investments	3,407
Proceeds received from property insurance claims	3,804
Net cash provided by (used in) investing activities	3,244	(3,978)
Cash flows from financing activities:
Intercompany loan proceeds	(28,618)	3,594
Distributions to non-controlling interest	(241)	(310)
Net cash (used in) provided by financing activities	(28,859)	3,284
Effect of exchange rate changes in cash and cash equivalents	(683)	798
Net (decrease) increase in cash and cash equivalents	(18,508)	4,006
Cash and cash equivalents at beginning of period	26,800	21,067
Cash and cash equivalents at end of period	8,292	25,073
LAMAR MEDIA CORP. AND SUBSIDIARIES [Member] \| Eliminations [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	(220,034)	(187,751)
Cash flows from investing activities:
Investment in subsidiaries	16,165	28,101
Decrease (increase) in intercompany notes receivable	(28,618)	3,594
Net cash provided by (used in) investing activities	(12,453)	31,695
Cash flows from financing activities:
Intercompany loan proceeds	28,618	(3,594)
Dividends (to) from parent	220,034	187,751
Contributions from (to) parent	(16,165)	(28,101)
Net cash (used in) provided by financing activities	$ 232,487	$ 156,056

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