Intangible Assets, Net (Gross And Net Carrying Amounts For Each Major Class Of Intangible Assets) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 2,722,784	$ 2,163,468
Accumulated amortization	(601,395)	(523,684)
Net book value	2,121,389	1,639,784
Current contract intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,841,744	1,391,001
Accumulated amortization	(384,926)	(333,522)
Net book value	1,456,818	1,057,479
Network location intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	881,040	772,467
Accumulated amortization	(216,469)	(190,162)
Net book value	$ 664,571	$ 582,305