Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	$ 5,947,855
Other comprehensive (loss) income before reclassifications	(41,528)
Amounts reclassified from accumulated other comprehensive income	(1,975)
Ending Balance	5,879,501
Deferred net losses from terminated hedges	300	$ 1,300
Net unrealized (loss) gain on derivative instruments
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	9,716
Other comprehensive (loss) income before reclassifications	(31,716)
Amounts reclassified from accumulated other comprehensive income	(965)
Ending Balance	(22,965)
Net unrealized gain on marketable securities
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	1,093
Other comprehensive (loss) income before reclassifications	1,276
Amounts reclassified from accumulated other comprehensive income	0
Ending Balance	2,369
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	15,108
Ending Balance	(28,395)
Joint venture | Net unrealized (loss) gain on derivative instruments
Accumulated Other Comprehensive Income (Loss) of the Company [Roll Forward]
Beginning Balance	4,299
Other comprehensive (loss) income before reclassifications	(11,088)
Amounts reclassified from accumulated other comprehensive income	(1,010)
Ending Balance	$ (7,799)