Real Estate And Accumulated Depreciation (Schedule Of Real Estate And Accumulated Depreciation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Real Estate And Accumulated Depreciation Disclosure
Description of Property	54,604 sites	[1]
Amount of Encumbrances	$ 2,120,804	[2]
Initial cost to the Company	0	[3]
Costs Capitalized Subsequent to Acquisition	0	[3]
Gross amount at which carried at close of the period.	8,316,547	[4]
Accumulated Depreciation	$ (2,968,230)
Date of construction	Various
Date Acquired	Various
Life on which depreciation in latest income statement is computed	Up to 20 years
Percentage Of Gross Amounts Maximum	5.00%

[1] No single site exceeds 5% of the aggregate gross amounts at which the assets were carried at the close of the period set forth in the table above.

[2] Certain assets secure debt of approximately $2.1 billion.

[3] The Company has omitted this information, as it would be impracticable to compile such information on a site-by-site basis.

[4] Does not include sites under construction accounts.