Income Taxes - Deferred Tax Asset (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss	$ 424,112	$ 427,245
Intangible assets	1,912	2,958
Environmental credit obligations	40,097	25,994
Other	16,137	22,551
Total deferred tax assets	482,258	478,748
Valuation allowance	(421,387)	(411,422)
Net deferred tax assets	60,871	67,326
Deferred tax liabilities:
Inventory	9,820	10,328
Property and equipment	56,436	58,122
Investment in Laramie Energy	0	4,522
Total deferred tax liabilities	66,256	72,972
Total deferred tax liability, net	$ (5,385)	$ (5,646)