Property And Equipment, Net (Property And Equipment, Net (Including Assets Held Under Capital Leases)) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,491,126	$ 5,232,033
Less: accumulated depreciation	(2,678,780)	(2,439,957)
Property and equipment, net	2,812,346	2,792,076
Towers and Related Components [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,772,807	4,563,756
Construction-In-Process [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	34,689	38,926
Furniture, equipment and vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	53,260	50,671
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 630,370	$ 578,680