Investments in Unconsolidated Entities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments In Unconsolidated Joint Ventures [Line Items]
Total revenues	$ 3,859,826	$ 3,343,546	$ 2,880,608
Net income	888,549	512,300	138,280
Net real estate investments	26,888,685	22,851,196
Total other assets	2,135,160	2,111,727
Total assets	29,023,845	24,962,923
Total liabilities	13,664,877	11,403,465
Redeemable noncontrolling interests	183,083	86,409
Total equity	15,175,885	13,473,049	11,756,331	$ 10,520,519
Non Controlling [Member]
Investments In Unconsolidated Joint Ventures [Line Items]
Total revenues	2,947,993	1,879,240	1,739,381
Net income	(40,116)	5,002	$ (15,265)
Net real estate investments	1,359,034	2,107,201
Total other assets	2,241,084	992,637
Total assets	3,600,118	3,099,838
Total liabilities	2,769,093	1,769,457
Redeemable noncontrolling interests	14,024	40,525
Total equity	$ 817,001	$ 1,289,856