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Investment maturity period.

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Number of Advertising displays as of the balance sheet date.

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- Definition

Number of states in which the entity operates with logo sign business as of the balance sheet date.

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- Definition

Number Of States In Which Entity Operates With Transit Advertising Business

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Number Of Transit Advertising Displays

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- Definition

Percentage Net Income Available For Dividend Distribution

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- Definition

Consideration paid per share for dividends of preferred stock.

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Aggregate dividends paid during the period for each share of common stock outstanding.

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Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 405

-Section 45

-Paragraph 2

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Reporting Unit

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The number of states the entity operates in as of the balance sheet date.

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- Definition

Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (a)

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

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Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Reporting_Unit Billboard Transit State	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of advertising displays	144,000lamr_NumberOfAdvertisingDisplays
Number of states in which the company operates	44
Number of states in which the company operates logo sign business	23
Number of transit advertising displays	41,000lamr_NumberOfTransitAdvertisingDisplays
Number of states in which the company operates	16
Number of reporting units	2us-gaap_NumberOfReportingUnits
REIT threshold percentage of taxable income to be distributed to stockholders	90.00%
Distributions paid, preferred stockholders	$ 365us-gaap_DividendsPreferredStock	$ 365us-gaap_DividendsPreferredStock	$ 365us-gaap_DividendsPreferredStock
Distributions paid, preferred stockholders, per share	$ 63.80lamr_PreferredStockDividendShares	$ 63.80lamr_PreferredStockDividendShares	$ 63.80lamr_PreferredStockDividendShares
Dilutive shares	0	0	0
Non cash compensation expense	24,120us-gaap_ShareBasedCompensation	24,936us-gaap_ShareBasedCompensation	14,466us-gaap_ShareBasedCompensation
Investment maturity period	Three months or less
LAMAR MEDIA CORP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of advertising displays	144,000
Number of states in which the company operates	44
Number of states in which the company operates logo sign business	23
Non cash compensation expense	24,120	24,936	14,466
One-time Special Cash Distribution [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distributions paid	39,915
Distributions paid, per share	$ 0.42
Taxable Income Distribution [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Distributions paid	198,520
Distributions paid, per share	$ 2.08
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non cash compensation expense	9,652
Performance-Based Stock Incentive Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non cash compensation expense	14,210
Stock Awards to Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non cash compensation expense	$ 258
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated useful lives of Intangible assets	3 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated useful lives of Intangible assets	15 years