Property and Equipment, Net (Property and Equipment, Net (Including Assets Held Under Capital Leases)) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 6,114,942	$ 6,123,966
Less: accumulated depreciation	(3,506,416)	(3,446,640)
Property and equipment, net	2,608,526	2,677,326
Towers and Related Components [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	5,204,880	5,213,019
Construction-In-Process [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	34,040	38,065
Furniture, Equipment and Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	54,270	54,610
Land, Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 821,752	$ 818,272