Derivatives - Schedule of Pre-Tax Gain (Loss) Recognized in the Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Commodity derivatives | Cost of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	$ (2,755)	$ (1,247)	$ (3,259)	$ 3,685
J. Aron repurchase obligation derivative | Cost of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	13,388	8,800	(3,919)	15,142
MLC repurchase obligation derivative | Cost of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	9,603	0	(3,339)	0
Interest rate derivatives | Interest expense and financing costs, net
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax gains (losses)	$ (1,471)	$ 62	$ (1,470)	$ 1,298