Notes Payable and Unsecured Credit Facilities - Schedule of Debt Net of Unamortized Debt Premium (Discount) and Debt Issuance Costs (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term Debt		$ 3,726,754	$ 3,718,944
Fixed Rate Mortgage Loans [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date		Mar. 01, 2032
Debt, Weighted Average Contractual Interest Rate		3.90%
Debt, Weighted Average Effective Interest Rate		3.50%
Long-term Debt		$ 342,135	359,414
Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date		Mar. 15, 2049
Debt, Weighted Average Contractual Interest Rate		3.80%
Debt, Weighted Average Effective Interest Rate		4.00%
Long-term Debt		$ 3,248,373	3,243,991
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 3,726,754	3,718,944
Line of Credit [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date	[1]	Mar. 23, 2025
Debt, Weighted Average Contractual Interest Rate	[1]	5.00%
Debt, Weighted Average Effective Interest Rate	[1]	5.30%
London Interbank Offered Rate (LIBOR) [Member] | Variable Rate Mortgage Loans [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date	[2]	Jun. 02, 2027
Debt, Weighted Average Contractual Interest Rate	[2]	3.40%
Debt, Weighted Average Effective Interest Rate	[2]	3.70%
Long-term Debt	[2]	$ 136,246	$ 115,539

[1] Weighted-average effective rate for the Line is calculated based on a fully drawn Line balance using the period end variable rate.

[2] 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%.