Debt (Schedule of Lines of Credit Outstanding) (Details) - USD ($)		3 Months Ended
	Aug. 26, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 15, 2015
Line of Credit Facility [Line Items]
Document Period End Date		Mar. 31, 2022
Debt issuance costs, net of amortization		$ (2,579,000)		$ (2,738,000)
Debt Issuance Costs, Line of Credit Arrangements, Net		19,421,000		738,000
Letters of Credit Outstanding, Amount		1,500,000		1,700,000
Line of Credit Facility, Remaining Borrowing Capacity		35,000,000
Payments of Debt Issuance Costs	$ 0.1	$ 86,000	$ 595,000
Line of Credit Facility, Interest Rate at Period End		3.15%
Debt Issuance Costs, Gross		$ 100,000
Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit					$ (300,000,000)
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit		0		(2,000,000)
Line of Credit Facility, Maximum Borrowing Capacity		35,000,000			$ 325,000,000
Unsecured Debt [Member]
Line of Credit Facility [Line Items]
Long-term Line of Credit		$ (22,000,000)		$ 0