Summary of Significant Accounting Policies (Details) $ in Thousands	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Deferred Finance Costs, Net		$ 0
Other assets	$ 422,079	428,899
Mortgage notes payable, net	4,223,681	4,685,134
Notes, net	$ 4,360,137	5,848,956
Partially Owned Consolidated Properties	18
Partially Owned Consolidated Units	3,471
Noncontrolling Interests – Partially Owned Properties/Partners' equity	$ 4,399	4,608
Scenario, Previously Reported [Member]
Deferred Finance Costs, Net		54,004
Other assets		422,027
Mortgage notes payable, net		4,704,870
Notes, net		5,876,352
Limited Life Partnership Properties [Member]
Partially Owned Consolidated Properties	5
Noncontrolling Interests – Partially Owned Properties/Partners' equity	$ 9,400
Noncontrolling Interests Settlement Value	54,000
Other assets
Deferred Finance Costs, Net	6,100
Mortgage notes payable, net
Deferred Finance Costs, Net	18,300
Notes, net
Deferred Finance Costs, Net	$ 24,600
Adjustments for New Accounting Pronouncement [Member]
Deferred Finance Costs, Net		(54,004)
Other assets		6,872
Mortgage notes payable, net		(19,736)
Notes, net		$ (27,396)