Income Taxes - Components of Deferred Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Allowance for doubtful accounts	$ 255	$ 2,972
Accrued liabilities not deducted for tax purposes	4,703	37,764
Asset retirement obligation	79	70,166
Net operating loss carry forwards	11,881	138,865
Tax credit carry forwards	209	4,844
Charitable contributions carry forward	9	9
Property, plant and equipment	65
Investment in partnership	354
Gross deferred tax assets	17,555us-gaap_DeferredTaxAssetsGross	254,620us-gaap_DeferredTaxAssetsGross
Less: valuation allowance	(9)	(2,331)
Net deferred tax assets	17,546us-gaap_DeferredTaxAssetsNet	252,289us-gaap_DeferredTaxAssetsNet
Deferred tax liabilities:
Property, plant and equipment		(45,160)
Intangibles	(4,321)	(314,382)
Investment in partnerships		(1,519)
Gross deferred tax liabilities	(4,321)us-gaap_DeferredTaxLiabilities	(361,061)us-gaap_DeferredTaxLiabilities
Net deferred tax assets (liabilities)	13,225	(108,772)
Classification in the consolidated balance sheets:
Current deferred tax assets	729us-gaap_DeferredTaxAssetsNetCurrent	10,378us-gaap_DeferredTaxAssetsNetCurrent
Current deferred tax liabilities	0us-gaap_DeferredTaxLiabilitiesCurrent	0us-gaap_DeferredTaxLiabilitiesCurrent
Noncurrent deferred tax assets	12,496us-gaap_DeferredTaxAssetsNetNoncurrent
Noncurrent deferred tax liabilities		(119,150)
Net deferred tax assets (liabilities)	13,225	(108,772)
LAMAR MEDIA CORP [Member]
Deferred tax assets:
Allowance for doubtful accounts	255	2,972
Accrued liabilities not deducted for tax purposes	4,703	37,764
Asset retirement obligation	79	70,166
Net operating loss carry forwards	11,881	89,496
Tax credit carry forwards	209	19,615
Charitable contributions carry forward	9	9
Property, plant and equipment	65
Investment in partnership	354
Gross deferred tax assets	17,555	220,022
Less: valuation allowance	(9)	(1,760)
Net deferred tax assets	17,546	218,262
Deferred tax liabilities:
Property, plant and equipment		(45,160)
Intangibles	(4,321)	(313,746)
Investment in partnerships		(1,519)
Gross deferred tax liabilities	(4,321)	(360,425)
Net deferred tax assets (liabilities)	13,225	(142,163)
Classification in the consolidated balance sheets:
Current deferred tax assets	729	10,378
Current deferred tax liabilities	0	0
Noncurrent deferred tax assets	12,496
Noncurrent deferred tax liabilities		(152,541)
Net deferred tax assets (liabilities)	$ 13,225	$ (142,163)

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The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from currently nondeductible expenses in accrued liabilities, which can only be deducted for tax purposes when such items are actually incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.