Significant Accounting Policies Nature of Ops and Sign. Acctg Policies (Details Textuals) - USD ($) shares in Millions	1 Months Ended	12 Months Ended
	Apr. 17, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Property, Plant and Equipment [Line Items]
Impairments of unevaluated costs		$ 18,200,000	$ 0	$ 21,400,000
Ceiling test write-downs of oil and gas properties		0	0	0
Costs related to CO2 pipelines not placed into service		117,600,000
Amortization of intangible assets		2,400,000	2,400,000	$ 2,400,000
Impairment of long-lived assets		0
Issued pursuant to notes conversion, shares	55.2
Operating lease liabilities		$ 48,833,000			$ 55,800,000
Allowance for loan receivable			$ 16,900,000
Pipelines | Minimum
Property, Plant and Equipment [Line Items]
Useful life		20 years
Pipelines | Maximum
Property, Plant and Equipment [Line Items]
Useful life		50 years
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Useful life		5 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Useful life		10 years
Furniture and Fixtures | Minimum
Property, Plant and Equipment [Line Items]
Useful life		5 years
Furniture and Fixtures | Maximum
Property, Plant and Equipment [Line Items]
Useful life		10 years
Computer Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life		3 years
Computer Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life		5 years