Corporate Indebtedness (Schedule of Consolidated Interest Expense, Excluding Capitalized Interest)(Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Interest expense
Interest expense before capitalized interest	$ 72,422	$ 102,155
Interest capitalized	(6,279)	(6,618)
Interest income	(521)	(865)
Interest expense, net	$ 65,622	$ 94,672