Basis of Presentation and Summary of Significant Accounting Policies (Impact on new accounting pronouncement adoption) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables and other assets	$ 304,509	$ 299,709
Notes Payable to Banks	543,196	542,880
Mortgage notes payable, net	$ 1,234,599	1,235,502
As previously filed on December 31, 2015 Consolidated Balance Sheet
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables and other assets		309,663
Notes Payable to Banks		550,000
Mortgage notes payable, net		1,238,336
Receivables and Other Assets | Impact of Adoption of ASU No. 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt Issuance Costs, Net		(9,954)
Notes Payable to Banks | Impact of Adoption of ASU No. 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt Issuance Costs, Net		(7,120)
Mortgage Notes Payable | Impact of Adoption of ASU No. 2015-03
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt Issuance Costs, Net		$ (2,834)