Related Party Transactions - Other Agreements (Details) - Martin Resource Management $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) bbl_per_day
Cross Tolling Agreement
Related Party Transaction [Line Items]
Production minimum per day (in bbl) | bbl_per_day		6,500
Capital recovery fee reimbursement, expired		$ 2,088
Annual escalation benchmark percentage		3.00%
Sulfuric Acid Sales Agency Agreement
Related Party Transaction [Line Items]
Partnership notice period to terminate agreement (in days)		90 days
Scenario, Forecast | Cross Tolling Agreement
Related Party Transaction [Line Items]
Capital recovery fee reimbursement, expired	$ 2,586
Annual revenue decrease from contract expiration	$ 2,145