Commitments and Contingencies Environmental Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Other noncurrent liabilities
Environmental remediation obligations [Member]
Environmental remediation obligation, minimum	$ 19,000
Environmental remediation obligation, maximum	29,900
Accrual for environmental loss contingencies	23,729	$ 25,286	$ 26,367	$ 26,866
Deductions	(2,262)	(2,520)	(2,033)
Charged to costs and expense	705	$ 1,439	$ 1,534
Combined Manufacturing Sites [Member] | Manufactured Gas Plants [Member]
Accrual for environmental loss contingencies	18,200
Aberdeen South Dakota Site [Member] | Manufactured Gas Plants [Member]
Accrual for environmental loss contingencies	7,200
Environmental remediation obligation, to be incurred during next 5 years	$ 2,100