Significant Accounting Policies Significant Accounting Policies (Details Textuals) (Details) - USD ($) $ in Thousands, shares in Millions	1 Months Ended	12 Months Ended
	Apr. 17, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Restricted Cash and Cash Equivalents		$ 16,389	$ 15,934	$ 15,400
Impairments of unevaluated costs			21,400	21,000
Ceiling test write-down		0	0	810,921
CO2 pipelines not placed in service		122,500
Amortization of Intangible Assets		2,400	2,400	2,300
Loan receivable		16,900
Debt Conversion, Converted Instrument, Shares Issued	55.2
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		54,949	$ 15,992	$ 17,050	$ 17,502
Operating Lease, Liability		55,000
Allowance for loan receivable		$ 16,900
Pipelines [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		20 years
Pipelines [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		50 years
Furniture and Fixtures [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Furniture and Fixtures [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		10 years
Computer Equipment [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		3 years
Computer Equipment [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Vehicles [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Vehicles [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		10 years