U.S. and Foreign Components of Earnings (Loss) before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Components of Income Before Income Tax Domestic and Foreign [Abstract]
U.S.					$ 16,641	$ (59,353)	$ (94,371)
Foreign					(1,468)	(4,218)	232
Income (loss) before income tax expense	23,151	12,872	5,005	11,054	15,173	(63,571)	(94,139)
LAMAR MEDIA CORP
Components of Income Before Income Tax Domestic and Foreign [Abstract]
U.S.					16,999	(59,193)	(92,201)
Foreign					(1,468)	(4,218)	232
Income (loss) before income tax expense	$ 23,225	$ 12,950	$ 5,278	$ 11,330	$ 15,531	$ (63,411)	$ (91,969)

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The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Subparagraph 1(i)

-Article 4

+ Details

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

+ References

+ Details

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- Definition

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

+ Details

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