Stockholders' Equity (Narrative) (Details) (USD $)	1 Months Ended	2 Months Ended	12 Months Ended			22 Months Ended	23 Months Ended
	Aug. 30, 2005	Feb. 21, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Feb. 11, 2013
Warrants exercisable for shares of common stock	6,800,000
Class of warrant or right, number of securities called by warrants or rights	3.575
Common stock at an exercise price of warrant	32
Treasury stock shares acquired		15,790	872,005			4,300,000	4,300,000
Treasury stock value acquired cost method		$ 1,200,000	$ 62,728,000	$ 423,932,000	$ 420,789,000	$ 243,900,000	$ 245,200,000
Treasury stock amount paid in cash			62,728,000	437,402,000	430,618,000
Remaining stock value Of Buyback			1,300,000,000
Distributions Payable Upon Vesting RSU			700,000			700,000
SpectraSite [Member]
Warrants exercisable for shares of common stock	2.00
Treasury Stock
Treasury stock shares acquired			872,005	8,147,902	9,273,069
Treasury stock value acquired cost method			62,728,000	423,932,000	420,789,000
Two Thousand Eleven Buyback [Member]
Authorized Repurchase of common stock			$ 1,500,000,000