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

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Domestic Site Leasing Revenue [Member] | AT&T [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

31.10%

^[1]

27.20%

^[1]

29.70%

^[1]

25.80%

^[1]

Domestic Site Leasing Revenue [Member] | Sprint [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

25.10%

^[2]

30.80%

^[2]

26.20%

^[2]

30.40%

^[2]

Domestic Site Leasing Revenue [Member] | T-Mobile [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

19.10%

^[3]

18.10%

^[3]

19.40%

^[3]

17.90%

^[3]

Domestic Site Leasing Revenue [Member] | Verizon [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

14.20%

13.70%

14.00%

13.10%

International Site Leasing Revenue [Member] | Oi [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

46.20%

1.30%

43.10%

1.20%

International Site Leasing Revenue [Member] | Telefonica [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

27.20%

49.30%

30.20%

52.00%

International Site Leasing Revenue [Member] | Digicel [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

4.50%

11.80%

5.00%

12.00%

Site Development Revenue [Member] | Sprint [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

46.10%

^[2]

1.80%

^[2]

32.20%

^[2]

0.90%

^[2]

Site Development Revenue [Member] | Ericsson, Inc [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

16.10%

32.20%

17.20%

38.10%

Site Development Revenue [Member] | T-Mobile [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

7.40%

^[3]

10.50%

^[3]

8.90%

^[3]

7.90%

^[3]

Site Development Revenue [Member] | Verizon [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

10.00%

4.90%

9.80%

4.30%

Site Development Revenue [Member] | Alcatel-Lucent [Member]

Concentration Risk [Line Items]

Concentration risk percentage of revenue

0.70%

8.10%

2.50%

10.10%

[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.