Debt (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 29, 2029	Dec. 28, 2028	Feb. 25, 2028	Feb. 25, 2027	Aug. 08, 2026	Feb. 25, 2026	Aug. 08, 2025	Feb. 25, 2025	Aug. 08, 2024	Feb. 25, 2024	Dec. 31, 2022	Feb. 09, 2022	Feb. 07, 2022	Dec. 15, 2015	Jul. 30, 2015
Debt Instrument [Line Items]
Document Period End Date	Jun. 30, 2023
Debt Instrument, Interest Rate, Stated Percentage														3.15%
Payments of Debt Issuance Costs	$ 72,000	$ 86,000
Costs associated with amendment	2,214,000												$ 2,605,000
Line of Credit Facility, Remaining Borrowing Capacity	35,000,000
Senior Notes	336,016,000												335,825,000
Letters of Credit Outstanding, Amount	3,000,000												5,000,000
Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate															0.60%
Other Notes Payable	14,591,000												14,622,000		$ 14,400,000
2026 Notes
Debt Instrument [Line Items]
Senior Notes	75,000,000												75,000,000
2027 Notes
Debt Instrument [Line Items]
Senior Notes	37,500,000												37,500,000
2028 Notes
Debt Instrument [Line Items]
Senior Notes	125,000,000												125,000,000
2029 Notes
Debt Instrument [Line Items]
Senior Notes	100,000,000												100,000,000
Senior Notes
Debt Instrument [Line Items]
Costs associated with amendment	$ 1,484,000												$ 1,675,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity																$ 325,000,000	$ 35,000,000
Forecast [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five			$ 70,000,000
Long-Term Debt, Maturity, Year Two									$ 12,500,000	$ 25,000,000
Long-Term Debt, Maturity, Year Four						$ 25,000,000
Long-Term Debt, Maturity, Year One											$ 12,500,000	$ 25,000,000
Long-Term Debt, Maturity, Year Three							$ 50,000,000	$ 25,000,000
Long-Term Debt, Maturity, Year Five				$ 30	$ 25,000,000