Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2012 Y	Dec. 31, 2011
Summary of intangible assets
Gross Carrying Amount	$ 1,937,812	$ 1,928,647
Accumulated Amortization	1,502,079	1,451,767
Unamortizable Intangible Assets:
Goodwill gross carrying amount	1,681,805	1,680,483
Goodwill accumulated amortization	253,635	253,635
Customer lists and contracts [Member]
Summary of intangible assets
Estimated Life (Years), Minimum	7
Estimated Life (Years), Maximum	10
Gross Carrying Amount	469,837	468,371
Accumulated Amortization	455,228	451,524
Non-competition agreements [Member]
Summary of intangible assets
Estimated Life (Years), Minimum	3
Estimated Life (Years), Maximum	15
Gross Carrying Amount	63,622	63,592
Accumulated Amortization	62,282	61,849
Site locations [Member]
Summary of intangible assets
Estimated Life (Years), Maximum	15
Gross Carrying Amount	1,390,745	1,383,076
Accumulated Amortization	971,451	925,291
Other [Member]
Summary of intangible assets
Estimated Life (Years), Minimum	5
Estimated Life (Years), Maximum	15
Gross Carrying Amount	13,608	13,608
Accumulated Amortization	$ 13,118	$ 13,103

The accumulated amount of amortization of goodwill as of the balance sheet date.

No definition available.

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The accumulated amount of amortization of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

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- Definition

Sum of the gross carrying amounts before accumulated amortization as of the balance sheet date of all intangible assets having statutory or estimated useful lives. The aggregate gross carrying amount (including any previously recognized impairment charges) of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

+ References

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The maximum useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 35

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6904245&loc=d3e15217-109273

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 35

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6904245&loc=d3e15300-109273

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-Publisher FASB

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-Section 35

-Paragraph 2

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The minimum useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

+ References

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- Definition

Gross amount, as of the balance sheet date, of the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable), in excess of the fair value of net assets acquired in one or more business combination transactions.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a,h)

-URI http://asc.fasb.org/extlink&oid=6905597&loc=d3e13816-109267

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