Income Taxes - Components of Deferred Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Allowance for doubtful accounts	$ 2,972	$ 2,964
Accrued liabilities not deducted for tax purposes	37,764	35,580
Asset retirement obligation	70,166	65,994
Net operating loss carry forwards	138,865	163,597
Tax credit carry forwards	4,844	3,765
Charitable contributions carry forward	9	592
Gross deferred tax assets	254,620	272,492
Less: valuation allowance	(2,331)	(3,424)
Net deferred tax assets	252,289	269,068
Deferred tax liabilities:
Property, plant and equipment	(45,160)	(48,271)
Intangibles	(314,382)	(308,266)
Investment in partnerships	(1,519)	(1,244)
Gross deferred tax liabilities	(361,061)	(357,781)
Net deferred tax liabilities	(108,772)	(88,713)
Classification in the consolidated balance sheets:
Current deferred tax assets	10,378	10,817
Current deferred tax liabilities
Noncurrent deferred tax assets
Noncurrent deferred tax liabilities	(119,150)	(99,530)
Net deferred tax liabilities	(108,772)	(88,713)
LAMAR MEDIA CORP [Member]
Deferred tax assets:
Allowance for doubtful accounts	2,972	2,964
Accrued liabilities not deducted for tax purposes	37,764	35,580
Asset retirement obligation	70,166	65,994
Net operating loss carry forwards	89,496	114,361
Tax credit carry forwards	19,615	18,537
Charitable contributions carry forward	9	592
Gross deferred tax assets	220,022	238,028
Less: valuation allowance	(1,760)	(2,851)
Net deferred tax assets	218,262	235,177
Deferred tax liabilities:
Property, plant and equipment	(45,160)	(48,271)
Intangibles	(313,746)	(307,630)
Investment in partnerships	(1,519)	(1,244)
Gross deferred tax liabilities	(360,425)	(357,145)
Net deferred tax liabilities	(142,163)	(121,968)
Classification in the consolidated balance sheets:
Current deferred tax assets	10,378	10,817
Current deferred tax liabilities
Noncurrent deferred tax assets
Noncurrent deferred tax liabilities	(152,541)	(132,785)
Net deferred tax liabilities	$ (142,163)	$ (121,968)

Name:	lamr_ClassificationInConsolidatedBalanceSheetsAbstract
Namespace Prefix:	lamr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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.