Notes Payable and Unsecured Credit Facilities - Schedule of Debt Net of Unamortized Debt Premium (Discount) and Debt Issuance Costs (Parentheticals) (Details) - USD ($) $ in Thousands		Jun. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term Debt		$ 3,709,074	$ 3,726,754
Line of credit maximum amount		1,250,000
Variable Rate Mortgage Loans [Member] | SOFR [Member]
Debt Instrument [Line Items]
Long-term Debt	[1]	132,039	$ 136,246
Variable Rate Mortgage Loans [Member] | SOFR [Member] | Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 129,800
Variable Rate Mortgage Loans [Member] | Minimum [Member] | SOFR [Member]
Debt Instrument [Line Items]
Debt instrument, effective fixed interest rate		2.50%
Variable Rate Mortgage Loans [Member] | Maximum [Member] | SOFR [Member]
Debt Instrument [Line Items]
Debt instrument, effective fixed interest rate		6.00%

[1] Five of these six variable rate loans, representing $129.8 million of debt in the aggregate, have interest rate swaps in place to mitigate interest rate fluctuation risk. Based on these swap agreements, the effective fixed rates of the five loans range from 2.5% to 6.0%.