Derivatives. (Tables)

12 Months Ended

Dec. 31, 2020

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of derivatives not designated as hedging instruments

	As of December 31, 2020
	Assets			Liabilities
Type of Instrument	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Cash collateral balance	Other current assets	$	520
Commodity contracts	Derivative assets	$	17,149	Derivative liabilities	$	—

	As of December 31, 2019
	Assets			Liabilities
Type of Instrument	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Cash collateral balance	Other current assets	$	615
Commodity contracts	Derivative assets	$	2,438	Derivative liabilities	$	1,860

Schedule of recognized gains (losses) for derivatives

		Realized Gains (Losses)
		For the Years Ended December 31,
Type of Instrument	Statements of Operations Location	2020		2019
Commodity contracts	Cost of goods sold	$	2,102	$	(4,568	)
		$	2,102	$	(4,568	)

		Unrealized Gains
		For the Years Ended December 31,
Type of Instrument	Statements of Operations Location	2020		2019
Commodity contracts	Cost of goods sold	$	12,678	$	5,123
		$	12,679	$	5,123