Acquisitions - Van Hook Crude Acquisition Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Mar. 15, 2018
Business Acquisition [Line Items]
Total assets acquired	$ 293,525	$ 291,205	$ 15,549
Machinery, equipment and tooling
Business Acquisition [Line Items]
Total assets acquired	19,683	14,858	1,478
Plant and building
Business Acquisition [Line Items]
Total assets acquired	170,283	158,882	1,407
Railroad and sidings
Business Acquisition [Line Items]
Total assets acquired	$ 27,701	$ 27,347	9,926
Land improvements
Business Acquisition [Line Items]
Total assets acquired			$ 2,738