Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net (loss) income	$ (6,690)	$ 4,684
Items not involving cash:
Depreciation, depletion and amortization	3,980	1,492
Accretion of asset retirement obligations	394	141
Unrealized commodity derivative loss	8,850	249
Warrant derivative gain		(225)
Stock-based compensation expense	222	292
Investment in affiliates gain	(19)	(437)
Gain on derecognized equity investment in affiliate - Carbon California		(5,391)
Amortization of debt costs	277	89
Net change in:
Accounts receivable	6,091	(1,611)
Prepaid expenses, deposits and other current assets	375	448
Accounts payable, accrued liabilities and firm transportation contract obligations	(5,485)	907
Other non-current items	316	(543)
Net cash provided by operating activities	8,311	95
Cash flows from investing activities:
Development and acquisition of properties and equipment	(500)	(874)
Proceeds received - disposition of oil and gas properties	164
Proceeds received - Carbon California Acquisition		275
Net cash used in investing activities	(336)	(599)
Cash flows from financing activities:
Proceeds from credit facility and notes payable	3,000	3,000
Payments on credit facility and notes payable	(5,676)	(8)
Debt issuance costs	(41)
Distributions to (contributions from) non-controlling interests	22	(24)
Net cash (used in) provided by financing activities	(2,695)	2,968
Net increase in cash and cash equivalents	5,280	2,464
Cash and cash equivalents, beginning of period	5,736	1,650
Cash and cash equivalents, end of period	$ 11,016	$ 4,114