Variable Interest Entities - Summarized Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets:
Net Investment in Real Estate	$ 3,575,488	$ 3,255,240
Operating Lease Right-of-Use Assets	24,764	25,205
Cash and Cash Equivalents	52,268	162,090
Deferred Rent Receivable	97,088	84,567
Prepaid Expenses and Other Assets, Net	153,641	134,983
Total Assets	3,975,444	3,791,938
Liabilities and Partners' Capital:
Mortgage Loans Payable, Net	82,991	143,879
Accounts Payable, Accrued Expenses and Other Liabilities	146,778	120,292
Operating Lease Liabilities	22,426	22,826
Rents Received in Advance and Security Deposits	78,337	62,092
Total Liabilities and Equity/Partners' Capital	3,975,444	3,791,938
Other Real Estate Partnerships
Assets:
Net Investment in Real Estate	260,228	245,396
Operating Lease Right-of-Use Assets	13,109	13,173
Cash and Cash Equivalents	3,343	4,090
Deferred Rent Receivable	11,068	9,219
Prepaid Expenses and Other Assets, Net	10,602	8,077
Total Assets	298,350	279,955
Liabilities and Partners' Capital:
Mortgage Loans Payable, Net	2,469	6,292
Accounts Payable, Accrued Expenses and Other Liabilities	10,884	10,067
Operating Lease Liabilities	10,284	10,304
Rents Received in Advance and Security Deposits	3,875	4,130
Partners' Capital	270,838	249,162
Total Liabilities and Equity/Partners' Capital	$ 298,350	$ 279,955