Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit risk valuation adjustment	$ 200	$ 200
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	1,739	311
Total commodity derivative liabilities	(3,394)	(7,732)
Recurring | Non-trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	1,726	203
Total commodity derivative liabilities	(3,391)	(7,660)
Recurring | Trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	13	108
Total commodity derivative liabilities	(3)	(72)
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	0	104
Total commodity derivative liabilities	(6)	(5)
Recurring | Level 1 | Non-trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	0	104
Total commodity derivative liabilities	(6)	(5)
Recurring | Level 1 | Trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	0	0
Total commodity derivative liabilities	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	1,739	207
Total commodity derivative liabilities	(3,388)	(7,727)
Recurring | Level 2 | Non-trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	1,726	99
Total commodity derivative liabilities	(3,385)	(7,655)
Recurring | Level 2 | Trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	13	108
Total commodity derivative liabilities	(3)	(72)
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	0	0
Total commodity derivative liabilities	0	0
Recurring | Level 3 | Non-trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	0	0
Total commodity derivative liabilities	0	0
Recurring | Level 3 | Trading commodity derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total commodity derivative assets	0	0
Total commodity derivative liabilities	$ 0	$ 0