Goodwill and Other Intangible Assets (Rollforward) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Goodwill [Roll Forward]
Balance as of January 1, 2014	$ 3,849,888	[1]
Additions	40,437
Effect of foreign currency translation	(20,122)
Other	(3,653)	[2]
Balance as of September 30, 2014	3,866,550
Rental And Management | Domestic
Goodwill [Roll Forward]
Balance as of January 1, 2014	3,293,899	[1]
Additions	36,453
Effect of foreign currency translation	0
Other	0	[2]
Balance as of September 30, 2014	3,330,352
Rental And Management | International
Goodwill [Roll Forward]
Balance as of January 1, 2014	553,989	[1]
Additions	3,984
Effect of foreign currency translation	(20,122)
Other	(3,641)	[2]
Balance as of September 30, 2014	534,210
Network Development Services
Goodwill [Roll Forward]
Balance as of January 1, 2014	2,000	[1]
Additions	0
Effect of foreign currency translation	0
Other	(12)	[2]
Balance as of September 30, 2014	$ 1,988

[1] Balances have been revised to reflect purchase accounting measurement period adjustments.

[2] Other represents the goodwill associated with the Company’s operations in Panama and the Company’s third-party structural analysis business. Both businesses were sold during the three months ended September 30, 2014 (see note 7).