Segment Reporting - Information Concerning Business Activities (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment									3
Revenues	$ 644,788	$ 568,181	$ 486,744	$ 325,491	$ 249,755	$ 266,904	$ 152,286	$ 353,477	$ 2,025,204	$ 1,022,422	$ 1,811,247
Operating earnings (losses)									16,159	(5,747)	7,800
Depreciation and amortization									19,797	18,573	16,641
Property and equipment additions									12,382	5,008	35,743
Inventory liquidation gains and valuation (losses)	$ 10,300				$ (15,000)			$ 24,200	10,300	(15,000)	3,700
Crude Oil Marketing
Segment Reporting Information [Line Items]
Revenues									1,930,042	950,426	1,748,056
Depreciation and amortization									6,673	7,421	8,741
Property and equipment additions									3,245	3,130	7,249
Transportation
Segment Reporting Information [Line Items]
Revenues									94,498	71,724	63,191
Depreciation and amortization									12,099	10,963	7,900
Property and equipment additions									7,960	1,355	28,472
Pipeline and storage
Segment Reporting Information [Line Items]
Revenues									664	272	0
Depreciation and amortization									1,025	189	0
Property and equipment additions									1,169	0	0
Operating Segments
Segment Reporting Information [Line Items]
Revenues									2,029,390	1,022,422	1,811,247
Operating earnings (losses)									29,860	4,537	17,998
Operating Segments | Crude Oil Marketing
Segment Reporting Information [Line Items]
Revenues									1,930,042	950,426	1,748,056
Operating earnings (losses)									25,243	2,974	16,099
Operating Segments | Transportation
Segment Reporting Information [Line Items]
Revenues									94,824	71,724	63,191
Operating earnings (losses)									7,104	1,873	1,899
Operating Segments | Pipeline and storage
Segment Reporting Information [Line Items]
Revenues									4,524	272	0
Operating earnings (losses)									(2,487)	(310)	0
Other
Segment Reporting Information [Line Items]
Revenues									0	0	0
Operating earnings (losses)									0	0	0
Depreciation and amortization									0	0	0
Property and equipment additions									8	523	22
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues									(4,186)	0	0
Intersegment Eliminations | Crude Oil Marketing
Segment Reporting Information [Line Items]
Revenues									0	0	0
Intersegment Eliminations | Transportation
Segment Reporting Information [Line Items]
Revenues									(326)	0	0
Intersegment Eliminations | Pipeline and storage
Segment Reporting Information [Line Items]
Revenues									$ (3,860)	$ 0	$ 0