Acquisitions and Other Transactions (Narrative) (Details) (USD $)		0 Months Ended			0 Months Ended					0 Months Ended				0 Months Ended					0 Months Ended	3 Months Ended	0 Months Ended		3 Months Ended
	Mar. 31, 2013	Jun. 30, 2012 Brazil Vivo Acquisition [Member] sites	Mar. 30, 2012 Brazil Vivo Acquisition [Member] sites	Aug. 31, 2012 Brazil Vivo Acquisition [Member] sites	Dec. 08, 2011 Uganda Acquisition [Member] sites	Mar. 31, 2013 Uganda Acquisition [Member]	Dec. 31, 2012 Uganda Acquisition [Member]	Jun. 30, 2012 Uganda Acquisition [Member]	Jun. 29, 2012 Uganda Acquisition [Member] sites	Sep. 12, 2012 Mexico 2012 Acquisition [Member] sites	Mar. 31, 2013 Mexico 2012 Acquisition [Member]	Dec. 14, 2012 Mexico 2012 Acquisition [Member] sites	Sep. 27, 2012 Mexico 2012 Acquisition [Member] sites	Nov. 16, 2012 Mexico 2012 DEC Acquisition [Member] sites	Mar. 31, 2013 Mexico 2012 DEC Acquisition [Member]	Feb. 22, 2013 Mexico 2012 DEC Acquisition [Member] sites	Dec. 14, 2012 Mexico 2012 DEC Acquisition [Member] sites	Jan. 31, 2013 Mexico Axtel Acquisition [Member] sites	Dec. 20, 2012 Skyway Acquisition [Member] sites	Mar. 31, 2013 Skyway Acquisition [Member] sites	Dec. 28, 2012 Diamond Acquisition [Member] propertyinterests sites	Feb. 01, 2013 Colombia Movil Acquisition [Member] sites	Mar. 31, 2013 Colombia Movil Acquisition [Member] sites	Jul. 17, 2011 Colombia Movil Acquisition [Member]
Business Acquisition [Line Items]
Aggregate purchase price		$ 126,300,000	$ 151,700,000	$ 32,700,000		$ 169,200,000	$ 173,200,000	$ 171,500,000			$ 63,500,000				$ 64,900,000			$ 248,500,000	$ 169,600,000	$ 166,700,000	$ 322,500,000	$ 1,300,000		$ 182,000,000
Contingent consideration																						200,000
Value Added Tax Receivable											8,800,000				8,900,000
Business Acquisition, Cost of Acquired Entity, Cash Paid																			169,500,000	166,600,000	320,100,000
Number of communications sites acquired		700	800	192					962			2	279			2	188	883	318		316	13	1,539
Maximum number of communications sites to be acquired			1,500		1,000					348				198								2,126
Additional communications sites to be acquired		300
Number of property interests acquired under third party sites																					24
Number Of Sites Returned																				11
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	46,300,000																						31,900,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	0																						0
Updated Contingent Consideration Fair Value																							17,400,000
Ownership percentage					51.00%
Percentage of minority investors					49.00%
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability																							500,000
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed																			$ 100,000	$ 100,000	$ 2,400,000