Variable Interest Entities - Summarized Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Net Investment in Real Estate	$ 3,299,234	$ 3,255,240
Operating Lease Right-of-Use Assets	24,953	25,205
Cash and Cash Equivalents	97,723	162,090
Deferred Rent Receivable	89,985	84,567
Prepaid Expenses and Other Assets, Net	139,614	134,983
Total Assets	3,816,853	3,791,938
Liabilities and Partners' Capital:
Mortgage Loans Payable, Net	142,676	143,879
Accounts Payable, Accrued Expenses and Other Liabilities	94,110	120,292
Operating Lease Liabilities	22,608	22,826
Rents Received in Advance and Security Deposits	78,613	62,092
Total Liabilities and Equity/Partners' Capital	3,816,853	3,791,938
Other Real Estate Partnerships
Assets:
Net Investment in Real Estate	255,897	245,396
Operating Lease Right-of-Use Assets	13,152	13,173
Cash and Cash Equivalents	3,955	4,090
Deferred Rent Receivable	9,695	9,219
Prepaid Expenses and Other Assets, Net	9,800	8,077
Total Assets	292,499	279,955
Liabilities and Partners' Capital:
Mortgage Loans Payable, Net	6,250	6,292
Accounts Payable, Accrued Expenses and Other Liabilities	7,654	10,067
Operating Lease Liabilities	10,297	10,304
Rents Received in Advance and Security Deposits	4,128	4,130
Partners' Capital	264,170	249,162
Total Liabilities and Equity/Partners' Capital	$ 292,499	$ 279,955