Acquisitions (Schedule Of Acquisition Capital Expenditures) (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Acquisitions [Abstract]
Towers and related intangible assets	$ 29,315,000		$ 35,112,000		$ 948,045,000		$ 230,865,000
Ground lease land purchases	9,847,000	[1]	11,156,000	[1]	19,429,000	[1]	24,544,000	[1]
Total cash acquisition capital expenditures	39,162,000		46,268,000		967,474,000		255,409,000
Ground lease extensions	$ 3,700,000		$ 3,100,000		$ 5,000,000		$ 4,900,000

[1] In addition, the Company paid $3.7 million and $3.1 million for ground lease extensions and term easements during the three months ended June 30, 2014 and 2013, respectively, and $5.0 million and $4.9 million for ground lease extensions during the six months ended June 30, 2014 and 2013, respectively. The Company recorded these amounts in prepaid rent on its Consolidated Balance Sheets.