Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 13,291	$ 22,595
Accounts receivable:
Accounts receivable, gross	46,085	50,744
Allowance for credit losses	(2,768)	(1,097)
Accounts receivable, net	43,317	49,647
Inventories, net	2,842	3,730
Prepaid expenses	2,981	3,471
Derivative instruments	48,458	947
Total current assets	110,889	80,390
Property and equipment, net	8,603	9,217
Right of use assets from operating leases	2,097	2,444
Oil and natural gas properties, using the full cost method:
Proved	1,348,229	1,276,036
Unevaluated (excluded from the amortization base)	354,547	371,229
Accumulated depreciation, depletion, amortization and impairment	(848,002)	(754,379)
Total oil and natural gas properties	854,774	892,886
Held for sale assets	164	2,860
Derivative instruments	4,663	0
Other assets	2,136	635
Total assets	983,326	988,432
Current liabilities:
Accounts payable and accrued liabilities	65,966	64,558
Accrued payroll and benefits payable	6,514	10,963
Accrued interest payable	5,650	12,227
Revenue distribution payable	21,752	22,370
Long-term debt and financing leases, classified as current	497	594
Derivative instruments	0	11,957
Total current liabilities	100,379	122,669
Long-term debt and financing leases, less current maturities	436,755	421,392
Derivative instruments	0	5,075
Noncurrent operating lease obligations	579	917
Deferred compensation	467	165
Asset retirement obligations	22,544	21,073
Commitments and contingencies (Note 10)
Stockholders’ equity:
Preferred stock, 5,000,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.01 par value, 192,130,071 shares authorized; 48,390,691 issued and 47,915,880 outstanding at March 31, 2020 and 48,413,185 issued and 47,942,230 outstanding at December 31, 2019	484	485
Additional paid in capital	977,879	977,174
Treasury stock, at cost, 474,811 and 470,955 shares as of March 31, 2020, and December 31, 2019	(6,116)	(6,110)
Accumulated deficit	(549,645)	(554,408)
Total stockholders’ equity	422,602	417,141
Total liabilities and stockholders’ equity	$ 983,326	$ 988,432