Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deducted in Balance Sheet from Trade Accounts Receivable: Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 7,615	$ 7,615	$ 7,500
Charged to Costs and Expenses	5,947	6,034	5,484
Deductions	5,605	6,034	5,369
Balance at End of Period	7,957	7,615	7,615
Deducted in Balance Sheet from Trade Accounts Receivable: Allowance for Doubtful Accounts [Member] \| LAMAR MEDIA CORP [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	7,615	7,615	7,500
Charged to Costs and Expenses	5,947	6,034	5,484
Deductions	5,605	6,034	5,369
Balance at End of Period	7,957	7,615	7,615
Deducted in Balance Sheet from Intangible Assets: Amortization of Intangible Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	1,900,026	1,794,415	1,705,402
Charged to Costs and Expenses	96,139	106,533	102,941
Deductions	1,073	922	13,928
Balance at End of Period	1,995,092	1,900,026	1,794,415
Deducted in Balance Sheet from Intangible Assets: Amortization of Intangible Assets [Member] \| LAMAR MEDIA CORP [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	1,899,080	1,793,476	1,704,492
Charged to Costs and Expenses	96,139	106,533	102,941
Deductions	1,073	929	13,957
Balance at End of Period	$ 1,994,146	$ 1,899,080	$ 1,793,476

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

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Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

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