Corporate Indebtedness (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Debt Disclosure [Abstract]
Interest expense	$ 83,158	$ 78,770	$ 238,285	$ 234,303
Interest income	(782)	(544)	(1,861)	(1,441)
Interest expense, net	82,376	78,226	236,424	232,862
Interest capitalized	$ 7,972	$ 3,091	$ 18,689	$ 10,082