Consolidated balance sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 19,309	$ 31,154
Accounts receivable, net	88,543	87,699
Derivatives	88,965	198,805
Other current assets	14,445	14,574
Total current assets	211,262	332,232
Oil and natural gas properties, full cost method:
Evaluated properties	5,309,151	5,103,635
Unevaluated properties not being depleted	114,507	140,299
Less accumulated depletion and impairment	(4,448,482)	(4,218,942)
Oil and natural gas properties, net	975,176	1,024,992
Midstream service assets, net	128,052	131,725
Other fixed assets, net	40,951	43,538
Property and equipment, net	1,144,179	1,200,255
Derivatives	32,680	77,443
Investment in equity method investee	213,616	192,524
Other assets, net	8,414	10,833
Total assets	1,610,151	1,813,287
Current liabilities:
Accounts payable	14,500	14,181
Undistributed revenue and royalties	25,452	34,540
Accrued capital expenditures	39,860	61,872
Derivatives	1,480	0
Other current liabilities	72,520	106,222
Total current liabilities	153,812	216,815
Long-term debt, net	1,392,877	1,416,226
Derivatives	3,740	0
Asset retirement obligations	46,716	44,759
Other noncurrent liabilities	3,844	4,040
Total liabilities	1,600,989	1,681,840
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value, 50,000,000 shares authorized and zero issued as of June 30, 2016 and December 31, 2015	0	0
Common stock, $0.01 par value, 450,000,000 shares authorized and 227,197,566 and 213,808,003 issued and outstanding as of June 30, 2016 and December 31, 2015, respectively	2,272	2,138
Additional paid-in capital	2,216,036	2,086,652
Accumulated deficit	(2,209,146)	(1,957,343)
Total stockholders’ equity	9,162	131,447
Total liabilities and stockholders’ equity	$ 1,610,151	$ 1,813,287