Debt (Schedule of Lines of Credit Outstanding) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Dec. 09, 2022	Jul. 30, 2015
Line of Credit Facility [Line Items]
Document Period End Date	Sep. 30, 2024
Debt Issuance Costs, Net	$ (1,718,000)		$ (2,328,000)
Debt Issuance Costs, Line of Credit Arrangements, Net	1,718,000		2,328,000
Letters of Credit Outstanding, Amount	16,800,000		13,500,000
Line of Credit Facility, Remaining Borrowing Capacity	35,000,000.0
Payments of Debt Issuance Costs	0	$ 73,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit	0		0
Line of Credit Facility, Maximum Borrowing Capacity				$ 300,000,000	$ 35,000,000.0
Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit	$ 0		$ 0