Notes Payable (Narrative) (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2025 USD ($) yr	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Feb. 11, 2026 USD ($)	Nov. 01, 2023 USD ($)
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net		$ 10,100	$ 13,300
Unsecured notes payable		3,570,193	3,155,233
Carrying Value	[1]	3,900,800	3,485,600
Loss on early retirement of debt		0	921	$ 2,513
Available amount under unsecured credit facility		$ 1,200,000
Weighted average interest rate on floating rate debt	[2],[3]	3.90%
Weighted average maturity of indebtedness (including unsecured credit facility and unsecured short-term borrowings) (in years) | yr		4.5
Repayments of Notes Payable		$ 0	800,000	$ 437,749
Secured notes payable		330,597	330,358
Amortization of Debt Discount (Premium)			400
Letter Of Credit [Member]
Maximum Ability to Issue Letters of Credit Under Unsecured Credit Facility		50,000
Commercial Banks [Member]
Unsecured notes payable		629,900	217,900
Commercial Banks [Member] | Unsecured Credit Facility [Member]
Unsecured notes payable		0	178,000
Commercial Banks [Member] | Unsecured Credit Facility [Member] | Subsequent Event [Member]
Unsecured notes payable					$ 216,000
Senior Unsecured Notes [Member]
Unsecured notes payable		2,940,300	2,937,300
Unsecured Credit Facility [Member]
Value not exceeding the amount available under the unsecured credit facility		$ 600,000
Terms Of Bid Rate Loans		180 days
Unsecured Credit Facility [Member] | August 2022 Credit Agreement
Line of Credit Facility, Maximum Borrowing Capacity		$ 1,200,000
Unsecured Credit Facility [Member] | Commercial Banks [Member]
Notes payable, effective interest rate		5.14%
Floating Rate Notes Payable [Member]
Carrying Value	[4]	$ 1,133,900	$ 721,200
Weighted average interest rate on floating rate debt		4.40%	5.60%
4.87% Term loan Due 2026 | Commercial Banks [Member]
Unsecured notes payable		$ 39,900	$ 39,900
Debt Instrument, Maturity Date		Sep. 30, 2026
Notes payable, effective interest rate		4.87%	4.87%
3.78% - 4.04% Conventional Mortgage Notes, due 2026 - 2028 | Secured Debt [Member]
Secured notes payable		$ 291,500	$ 291,400
3.78% - 4.04% Conventional Mortgage Notes, due 2026 - 2028 | Secured Debt [Member] | Minimum [Member]
Debt Instrument, Maturity Date		Oct. 01, 2026
Notes payable, effective interest rate		3.78%
3.78% - 4.04% Conventional Mortgage Notes, due 2026 - 2028 | Secured Debt [Member] | Maximum [Member]
Debt Instrument, Maturity Date		Apr. 01, 2028
Notes payable, effective interest rate		4.04%
3.87% note, due 2028 | Secured Debt [Member]
Debt Instrument, Maturity Date		Jan. 01, 2028
Notes payable, effective interest rate		3.87%
Secured notes payable		$ 39,100	39,000
Term loan, due 2024 full value | Commercial Banks [Member]
Unsecured notes payable		40,000
5.00% Note, Due 2026 | Senior Unsecured Notes [Member]
Unsecured notes payable	[5]	$ 504,000	$ 503,300
Debt Instrument, Maturity Date		Nov. 03, 2026
Notes payable, effective interest rate		5.00%	5.00%			5.85%
Debt Instrument, Face Amount						$ 500,000
Derivative, Notional Amount						$ 500,000

[1] Balances are decreased by unamortized debt discounts, debt issuance costs, and fair market value adjustments, net of $10.1 million and $13.3 million as of December 31, 2025 and 2024, respectively.

[2] Includes all available extension options.

[3] Includes the effects of the applicable settled derivatives.

[4] Includes the senior unsecured notes payable and a term loan due in 2026 at December 31, 2025 and 2024. At December 31, 2025, the floating rate notes payable also includes the commercial paper notes. At December 31, 2024, it also reflects outstanding balances under our unsecured revolving credit facility.

[5] Balances are increased by $4.9 million and $5.3 million for fair value adjustments due to changes in benchmark interest rates related to these notes as of December 31, 2025 and 2024, respectively. See Note 9. "Derivative Financial Instruments and Hedging Activities," for further discussion.