Debt (Schedule of Lines of Credit Outstanding) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 15, 2015	Jul. 30, 2015
Line of Credit Facility [Line Items]
Document Period End Date	Sep. 30, 2023
Debt issuance costs, net of amortization	$ (1,983,000)		$ (2,605,000)
Debt Issuance Costs, Line of Credit Arrangements, Net	1,983,000		17,395,000
Letters of Credit Outstanding, Amount	10,000,000		5,000,000
Line of Credit Facility, Remaining Borrowing Capacity	35,000,000
Payments of Debt Issuance Costs	72,000	$ 86,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit	0		0
Line of Credit Facility, Maximum Borrowing Capacity				$ 325,000,000	$ 35,000,000
Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit	$ 0		$ (20,000,000)