Debt (Senior Notes, Term Loans, and Revolver) (Details)	1 Months Ended	3 Months Ended
	Jan. 31, 2023 USD ($)	Mar. 31, 2023 USD ($) option asset	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Debt
unamortized debt issuance costs on bonds		$ (10,101,000)		$ (10,693,000)
Number of extension options | option		2
Debt, net		$ 2,219,284,000		2,217,555,000
Unsecured Debt, Gross		824,656,000		823,662,000
Unamortized debt issuance costs on term loans		(2,975,000)		(3,126,000)
Amortization of deferred financing costs		$ 1,474,000	$ 1,684,000
Secured Debt [Member]
Debt
Number of Assets Encumbered | asset		15
The Revolver | Line of Credit
Debt
Maximum borrowing capacity		$ 600,000,000
Additional maturity term		1 year
Unsecured Debt		$ 0		0
Interest Rate		0.00%
Remaining borrowing capacity		$ 600,000,000
$400 Million Term Loan Maturing 2023
Debt
Maximum borrowing capacity				400,000,000
Repayments of Debt	$ 52,300,000
$400 Million Term Loan Maturing 2023 | Unsecured Debt
Debt
Maximum borrowing capacity		400,000,000
Unsecured Debt		$ 0		52,261,000
Interest Rate		0.00%
$400 Million Term Loan Maturing 2024 | Unsecured Debt
Debt
Maximum borrowing capacity		$ 400,000,000
Unsecured Debt		$ 151,683,000		151,683,000
Interest Rate		6.71%
$225 Million Term Loan Maturing 2023
Debt
Maximum borrowing capacity				225,000,000
Repayments of Debt	$ 41,700,000
$225 Million Term Loan Maturing 2023 | Unsecured Debt
Debt
Maximum borrowing capacity		$ 225,000,000
Proceeds from long-term lines of credit		95,000,000
Unsecured Debt		$ 0		41,745,000
Interest Rate		0.00%
$400 Million Term Loan Maturing 2025 [Member] | Unsecured Debt
Debt
Maximum borrowing capacity		$ 400,000,000
Unsecured Debt		$ 400,000,000		400,000,000
Interest Rate		3.27%
Conventional Mortgage Loan
Debt
Unsecured Debt		$ 821,681,000		820,536,000
$500 Million Senior Notes Due 2026 | Unsecured Debt
Debt
Debt Instrument, Interest Rate, Stated Percentage		3.75%
Senior Notes [Member]
Debt
Long-term Debt, Gross		$ 989,899,000		989,307,000
$500 Million Senior Notes Due 2029 | Unsecured Debt
Debt
Debt Instrument, Interest Rate, Stated Percentage		4.00%
$225 Million Term Loan Maturing 2024 | Unsecured Debt
Debt
Maximum borrowing capacity		$ 225,000,000
Unsecured Debt		$ 72,973,000		72,973,000
Interest Rate		4.57%
$200 Million Term Loan Maturing 2026
Debt
Additional maturity term		1 year
$200 Million Term Loan Maturing 2026 | Unsecured Debt
Debt
Maximum borrowing capacity		$ 200,000,000
Unsecured Debt		$ 200,000,000		105,000,000
Interest Rate		3.43%
Prepaid expenses and other assets
Debt
Deferred financing costs		$ 1,400,000		1,700,000
Fair Value, Inputs, Level 3 [Member] | Secured Debt [Member]
Debt
Secured Debt		407,704,000		407,712,000
Fair Value, Inputs, Level 3 [Member] | Unsecured Debt
Debt
Unsecured Debt		821,681,000		820,536,000
Level 1 | Senior Notes [Member]
Debt
Long-term Debt, Gross		1,000,000,000		1,000,000,000
Level 1 | $500 Million Senior Notes Due 2029
Debt
Long-term Debt, Gross		500,000,000		500,000,000
Level 1 | $500 Million Senior Notes Due 2026
Debt
Long-term Debt, Gross		$ 500,000,000		$ 500,000,000