Equity and Accumulated Other Comprehensive Loss, Net (Schedule of Accumulated Other Comprehensive Loss, Net) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 10,858,210	$ 11,049,450
Net current period change	4,266
Reclassification of foreign currency translation adjustment due to deconsolidation of Ascenty	21,687	0
Reclassification to interest expense from interest rate swaps	(2,005)
Ending balance	10,982,499	10,936,544
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(158,649)
Net current period change	7,880
Reclassification of foreign currency translation adjustment due to deconsolidation of Ascenty	21,687
Reclassification to interest expense from interest rate swaps	0
Ending balance	(129,082)
Cash flow hedge adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	17,264
Net current period change	(3,614)
Reclassification of foreign currency translation adjustment due to deconsolidation of Ascenty	0
Reclassification to interest expense from interest rate swaps	(2,005)
Ending balance	11,645
Foreign currency net investment hedge adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	25,738
Net current period change	0
Reclassification of foreign currency translation adjustment due to deconsolidation of Ascenty	0
Reclassification to interest expense from interest rate swaps	0
Ending balance	25,738
Accumulated other comprehensive income (loss), net
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(115,647)	(108,432)
Ending balance	$ (91,699)	$ (103,974)