Property And Equipment, Net (Property And Equipment, Net (Including Assets Held Under Capital Leases)) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,397,109	$ 5,232,033
Less: accumulated depreciation	(2,619,770)	(2,439,957)
Property and equipment, net	2,777,339	2,792,076
Towers And Related Components [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,691,935	4,563,756
Construction-In-Process [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	36,429	38,926
Furniture, Equipment And Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	51,713	50,671
Land, Buildings, and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 617,032	$ 578,680