Concentration Of Credit Risk (Summary Of Significant Customers And Percentage Of Total Revenue For Specified Time Periods Derived From Such Customers) (Details) (Revenue [Member])	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
AT&T [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	23.00%	[1]	20.50%	[1]	21.90%	[1]
Sprint [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	23.40%	[2]	25.00%	[2]	23.90%	[2]
T-Mobile [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	15.50%	[3]	17.30%	[3]	17.20%	[3]
Verizon [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	12.00%		11.30%		13.00%
Domestic Site Leasing Revenue [Member] | AT&T [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	30.10%	[1]	25.50%	[1]	26.10%	[1]
Domestic Site Leasing Revenue [Member] | Sprint [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	25.60%	[2]	30.90%	[2]	28.50%	[2]
Domestic Site Leasing Revenue [Member] | T-Mobile [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	19.20%	[3]	20.20%	[3]	19.70%	[3]
Domestic Site Leasing Revenue [Member] | Verizon [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	14.40%		13.30%		14.30%
International Site Leasing Revenue [Member] | Oi S.A. [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	44.30%		6.30%		0.10%
International Site Leasing Revenue [Member] | Telefonica [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	28.80%		44.20%		48.10%
International Site Leasing Revenue [Member] | Claro [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	8.00%		8.80%		12.60%
International Site Leasing Revenue [Member] | Digicel [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	4.90%		11.20%		19.50%
Site Development Revenue [Member] | Sprint [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	36.70%	[2]	1.50%	[2]	1.10%	[2]
Site Development Revenue [Member] | Ericsson, Inc [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	16.80%		34.50%		24.50%
Site Development Revenue [Member] | Verizon [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	10.10%		4.80%		8.90%
Site Development Revenue [Member] | MasTec Inc. [Member]
Concentration Risk [Line Items]
Concentration risk percentage of revenue	1.90%		4.60%		16.40%

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

[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.