Summary of Significant Accounting Policies - Condensed Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Real Estate Investment Property, Net	$ 2,502,638	$ 2,396,391
Total Assets	2,718,051	2,581,995
LIABILITIES AND EQUITY
Mortgage Loans Payable, Net	564,955	599,985
Total Liabilities and Equity/Partners' Capital	2,718,051	2,581,995
Other Real Estate Partnership
Assets:
Real Estate Investment Property, Net	306,866	278,720
Other Assets	20,478	21,078
Total Assets	327,344	299,798
LIABILITIES AND EQUITY
Mortgage Loans Payable, Net	77,445	81,231
Other Liabilities, Net	43,103	10,656
Partners' Capital	206,796	207,911
Total Liabilities and Equity/Partners' Capital	$ 327,344	$ 299,798