Derivatives - Schedule of Pre-Tax Gain (Loss) Recognized in the Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Commodity derivatives | Cost of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	$ (504)	$ 4,932
J. Aron repurchase obligation derivative | Cost of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	(17,307)	6,342
MLC repurchase obligation derivative | Cost of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	(12,942)	0
Interest rate derivatives | Interest expense and financing costs, net
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	$ 1	$ 1,236