Consolidated balance sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 35,024	$ 32,672
Accounts receivable, net	72,107	86,867
Derivatives	42,985	20,947
Other current assets	17,548	14,291
Total current assets	167,664	154,777
Oil and natural gas properties, full cost method:
Evaluated properties	5,703,873	5,488,756
Unevaluated properties not being depleted	203,888	221,281
Less accumulated depletion and impairment	(4,578,831)	(4,514,183)
Oil and natural gas properties, net	1,328,930	1,195,854
Midstream service assets, net	128,941	126,240
Other fixed assets, net	41,415	44,773
Property and equipment, net	1,499,286	1,366,867
Derivatives	12,807	8,718
Investment in equity method investee	249,492	243,953
Other assets, net	12,005	8,031
Total assets	1,941,254	1,782,346
Current liabilities:
Accounts payable	10,777	15,054
Undistributed revenue and royalties	32,166	26,838
Accrued capital expenditures	53,700	30,845
Derivatives	653	20,993
Other current liabilities	74,787	94,215
Total current liabilities	172,083	187,945
Long-term debt, net	1,390,277	1,353,909
Derivatives	0	5,694
Asset retirement obligations	51,034	50,604
Other noncurrent liabilities	3,457	3,621
Total liabilities	1,616,851	1,601,773
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.01 par value, 50,000,000 shares authorized and zero issued as of June 30, 2017 and December 31, 2016	0	0
Common stock, $0.01 par value, 450,000,000 shares authorized and 242,534,185 and 241,929,070 issued and outstanding as of June 30, 2017 and December 31, 2016, respectively	2,425	2,419
Additional paid-in capital	2,410,674	2,396,236
Accumulated deficit	(2,088,696)	(2,218,082)
Total stockholders' equity	324,403	180,573
Total liabilities and stockholders' equity	$ 1,941,254	$ 1,782,346