Variable Interest Entities - Summarized Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Net Investment in Real Estate	$ 2,861,860	$ 2,705,826
Total Assets	3,142,691	2,941,062
LIABILITIES AND PARTNERS' CAPITAL
Mortgage Loans Payable, Net	296,470	450,056
Total Liabilities and Equity/Partners' Capital	3,142,691	2,941,062
Other Real Estate Partnerships
ASSETS
Net Investment in Real Estate	260,528	270,708
Other Assets, Net	25,059	23,530
Total Assets	285,587	294,238
LIABILITIES AND PARTNERS' CAPITAL
Mortgage Loans Payable, Net	20,497	61,256
Other Liabilities, Net	9,045	9,283
Partners' Capital	256,045	223,699
Total Liabilities and Equity/Partners' Capital	$ 285,587	$ 294,238