Inventories (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Petroleum products	$ 5,840,000	$ 2,721,000
Crude oil	37,661,000	5,271,000
Caustic soda	5,167,000	5,965,000
NaHS	9,101,000	10,845,000
Raw materials - Alkali Operations	7,120,000	6,238,000
Work-in-process - Alkali Operations	9,355,000	8,579,000
Finished goods, net - Alkali Operations	13,002,000	14,168,000
Materials and supplies, net - Alkali Operations	12,631,000	11,350,000
Inventories	99,877,000	65,137,000
Inventory Write-down	$ 5,000,000.0	$ 0