Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 14,452	$ 9,892
Accounts receivable, net
Oil and natural gas sales	12,032	12,912
Joint interest and other	1,567	982
Related party	853	878
Prepaid and other current assets	12,331	8,696
Derivative asset	384
Note receivable - related party		5,828
Inventory	4,804	5,167
Total current assets	46,423	44,355
Oil and natural gas properties (successful efforts method)
Proved	170,237	163,006
Unproved	14,911	15,695
Equipment and other property	13,091	14,408
Property and equipment, gross	198,239	193,109
Less accumulated depreciation, depletion and amortization	(108,646)	(105,850)
Property and equipment, net	89,593	87,259
Other long-term assets:
Other assets	3,107	986
Note receivable - related party	4,150
Total other assets	7,257	986
Total assets	143,273	132,600
Current liabilities:
Accounts payable	6,067	3,896
Accounts payable - related party	3,552	2,922
Accrued liabilities	13,956	13,073
Derivative liability	414
Loans payable	18,912	22,000
Total current liabilities	42,901	41,891
Long-term liabilities:
Asset retirement obligations	4,836	4,667
Accrued liabilities	9,994	7,259
Deferred income taxes	22,720	20,314
Loans payable	7,143
Total long-term liabilities	44,693	32,240
Total liabilities	87,594	74,131
Commitments and contingencies
Shareholders' equity:
Common shares, $0.10 par value, 200,000,000 shares authorized; 57,708,698 shares and 52,413,588 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively	5,771	5,241
Treasury stock	(970)	(970)
Additional paid-in-capital	580,843	577,488
Accumulated other comprehensive loss	(145,855)	(142,021)
Accumulated deficit	(430,160)	(427,319)
Total shareholders' equity	9,629	12,419
Total liabilities, Series A preferred shares and shareholders' equity	143,273	132,600
Series A Preferred Shares [Member]
Long-term liabilities:
Preferred shares, value	21,300	21,300
Related Party [Member] | Series A Preferred Shares [Member]
Long-term liabilities:
Preferred shares, value	$ 24,750	$ 24,750