Supplemental Cash Flow Disclosure (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Cash paid during the period for:
Interest			$ 4,536	$ 909
Non-cash transactions:
Capital expenditures included in accounts payable and accrued liabilities			39	(161)
Adjustments to OIE Membership Acquisition purchase price			1,317
Increase in asset retirement obligations				3,560
Non-cash acquisition of Carbon California interests				(18,906)
Carbon California Acquisition on February 1, 2018				17,114
Obligations assumed with Seneca asset purchase				330
Accrued dividend for convertible preferred stock				71
Beneficial conversion feature for convertible preferred stock		$ 1,125		1,125
Exercise of warrant derivative				$ (1,792)