Schedule III - Schedule of Real Estate and Accumulated Depreciation (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 Displays	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of advertising displays	317,597
Encumbrances	$ 0
Initial Cost	0
Gross Carrying Amount	2,520,644,000	2,459,425,000	2,378,940,000
Accumulated Depreciation	(1,903,434,000)	(1,799,325,000)	(1,657,784,000)
Construction Date	Various
Acquisition Date	Various
LAMAR MEDIA CORP [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of advertising displays	317,597
Encumbrances	0
Initial Cost	0
Gross Carrying Amount	2,520,644,000	2,459,425,000	2,378,940,000
Accumulated Depreciation	$ (1,903,434,000)	$ (1,799,325,000)	$ (1,657,784,000)
Construction Date	Various
Acquisition Date	Various
Minimum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful Lives	5 years
Minimum [Member] | LAMAR MEDIA CORP [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful Lives	5 years
Maximum [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful Lives	20 years
Maximum [Member] | LAMAR MEDIA CORP [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful Lives	20 years