Intangible Assets, Net (Gross and Net Carrying Amounts for each Major Class of Intangible Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 6,432,059	$ 6,761,075
Accumulated amortization	(3,257,492)	(3,134,302)
Net book value	3,174,567	3,626,773
Current Contract Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	4,703,085	4,996,591
Accumulated amortization	(2,298,491)	(2,218,404)
Net book value	2,404,594	2,778,187
Network Location Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,728,974	1,764,484
Accumulated amortization	(959,001)	(915,898)
Net book value	$ 769,973	$ 848,586