Intangible Assets, Net (Gross And Net Carrying Amounts For Each Major Class Of Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 5,657,316	$ 5,351,157
Accumulated amortization	(2,000,392)	(1,615,744)
Net book value	3,656,924	3,735,413
Current Contract Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	4,141,968	3,904,864
Accumulated amortization	(1,401,025)	(1,118,493)
Net book value	2,740,943	2,786,371
Network Location Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,515,348	1,446,293
Accumulated amortization	(599,367)	(497,251)
Net book value	$ 915,981	$ 949,042