Debt and Financing Obligation (Covenants) (Details) - Credit Agreement and Partner Revolver	Dec. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Maximum consolidated leverage ratio	4.50
Minimum consolidated interest coverage ratio	2.50
SunCoke Energy Partners, L.P.
Line of Credit Facility [Line Items]
Cross default covenant threshold	$ 35,000,000