Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 32,648	$ 37,446
Accounts receivable, net	52,686	66,087
Inventories, net	4,142	4,059
Prepaid expenses	1,774	2,814
Derivative instruments	4,524	24,025
Total current assets	95,774	134,431
Property and equipment, net	36,265	43,096
Right of use assets from operating leases	9,005
Oil and natural gas properties, using the full cost method:
Proved	1,107,203	915,333
Unevaluated (excluded from the amortization base)	426,738	466,616
Accumulated depreciation, depletion, amortization and impairment	(384,401)	(221,431)
Total oil and natural gas properties	1,149,540	1,160,518
Derivative instruments	221	2,199
Other assets	411	425
Total assets	1,291,216	1,340,669
Current liabilities:
Accounts payable and accrued liabilities	73,770	73,779
Accrued payroll and benefits payable	7,807	10,976
Accrued interest payable	12,207	13,359
Revenue distribution payable	26,825	26,225
Long-term debt and financing leases, classified as current	11,502	12,371
Derivative instruments	4,802	0
Total current liabilities	136,913	136,710
Long-term debt and financing leases, less current maturities	382,295	295,100
Derivative instruments	9,196	1,542
Noncurrent operating lease obligations	2,075
Deferred compensation	693	540
Asset retirement obligations	22,300	22,090
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; 46,885,198 issued and 46,417,442 outstanding at June 30, 2019 and 46,651,616 issued and 46,390,513 outstanding at December 31, 2018	469	467
Additional paid in capital	977,611	974,616
Treasury stock, at cost, 467,756 and 261,103 shares as of June 30, 2019 and December 31, 2018	(6,107)	(4,936)
Accumulated deficit	(234,229)	(85,460)
Total stockholders' equity	737,744	884,687
Total liabilities and stockholders' equity	$ 1,291,216	$ 1,340,669