Revenue from Contracts with Customers - Narrative (Details) T in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) T
Cokemaking
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Unsatisfied performance obligations capacity (in tons) | T	16.6
Average remaining term	5 years
Logistics
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Average remaining term	3 years
Performance obligation amount | $	$ 41.3