Intangible Assets ( Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Change in goodwill balance	$ 0	$ 0
Total amortization expense of intangible assets	2,000,000	2,000,000	$ 2,500,000
Domestic Coke | Operating Segments
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 3,400,000	$ 3,400,000
Convent Marine Terminal | Permits
Finite-Lived Intangible Assets [Line Items]
Useful life	27 years
Average remaining renewal term	5 years 4 months 24 days