Notes Payable and Unsecured Credit Facilities - Schedule of Debt Net of Unamortized Debt Premium (Discount) and Debt Issuance Costs (Parentheticals) (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term Debt		$ 3,726,754	$ 3,718,944
Variable Rate Mortgage Loans [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Long-term Debt	[1]	136,246	$ 115,539
Variable Rate Mortgage Loans [Member] | London Interbank Offered Rate (LIBOR) [Member] | Interest Rate Swap [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 132,100
Variable Rate Mortgage Loans [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, effective fixed interest rate		2.50%
Variable Rate Mortgage Loans [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, effective fixed interest rate		4.10%

[1] Five of these six variable rate loans, representing $132.1 million of debt in the aggregate, have interest rate swaps in place to mitigate interest rate fluctuation risk. With these swap agreements, the fixed rates of the loans range from 2.5% to 4.1%.