Concentration Of Credit Risk (Summary Of Significant Customers And Percentage Of Total Revenue For Specified Time Periods Derived From Such Customers) (Details)	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Domestic Site Leasing Revenue [Member] | AT&T [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	29.60%	[1]	25.40%	[1]	29.00%	[1]	25.10%	[1]
Domestic Site Leasing Revenue [Member] | Sprint [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	26.30%	[2]	30.10%	[2]	26.70%	[2]	30.20%	[2]
Domestic Site Leasing Revenue [Member] | T-Mobile [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	19.20%	[3]	17.90%	[3]	19.50%	[3]	17.90%	[3]
Domestic Site Leasing Revenue [Member] | Verizon [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	13.90%		12.80%		13.80%		12.80%
International Site Leasing Revenue [Member] | Oi [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	49.50%		1.20%		41.00%		1.20%
International Site Leasing Revenue [Member] | Telefonica [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	26.00%		53.90%		30.40%		53.40%
International Site Leasing Revenue [Member] | Digicel [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	4.40%		12.00%		5.30%		12.10%
Site Development Revenue [Member] | Sprint [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	30.00%	[2]	0.80%	[2]	24.50%	[2]	0.50%	[2]
Site Development Revenue [Member] | Ericsson, Inc [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	17.20%		41.80%		17.80%		41.20%
Site Development Revenue [Member] | T-Mobile [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	10.20%	[3]	7.00%	[3]	9.70%	[3]	6.50%	[3]
Site Development Revenue [Member] | Verizon [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	11.90%		4.00%		9.70%		4.00%
Site Development Revenue [Member] | Alcatel-Lucent [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	2.60%		10.90%		3.60%		11.10%

[1] Prior year amounts have been adjusted to reflect the merger of AT&T Wireless and Cricket.

[2] Prior year amounts have been adjusted to reflect the merger of Sprint and Clearwire.

[3] Prior year amounts have been adjusted to reflect the merger of T-Mobile and Metro PCS.