Acquisitions - Additional Information (Detail)	3 Months Ended			9 Months Ended
	Sep. 30, 2013 USD ($) site Tower	Jun. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2013 Brazil Acquisition [Member] USD ($)	Sep. 30, 2013 Brazil [Member] USD ($)	Sep. 30, 2013 Brazil [Member] Foreign Exchange Forward [Member] USD ($)	Jul. 26, 2013 Brazil [Member] Foreign Exchange Forward [Member] USD ($)	Jul. 26, 2013 Brazil [Member] Foreign Exchange Forward [Member] BRL	Oct. 28, 2013 Brazil [Member] Subsequent Event [Member] Foreign Exchange Forward [Member] USD ($)	Oct. 28, 2013 Brazil [Member] Subsequent Event [Member] Foreign Exchange Forward [Member] BRL
Business Acquisition [Line Items]
Number of towers acquired	279
Additional communication sites	4
Acquisition of capital expenditures	$ 91,646,000		$ 31,598,000	$ 348,365,000	$ 982,989,000	$ 175,900,000
Ground lease extensions	2,800,000		1,200,000	7,600,000	4,700,000
Purchase price allocation adjustment to reclassify from Property and Equipment to Intangible Assets		54,100,000
Estimated contingent consideration fair value	100,000		500,000	1,900,000	1,300,000
Potential obligation recorded in accrued expenses				26,000,000
Foreign currency forward contracts, notional amount									305,000,000	697,100,000	314,000,000	687,500,000
Foreign currency forward contracts, unrealized gain								6,900,000
Foreign currency forward contracts, proceeds received				$ 182,855,000			$ 14,100,000