Consolidated Balance Sheets - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 2,099,000	$ 9,540,000
Accounts receivable, net	111,100,000	107,441,000
Derivative assets, current	10,928,000
Other current assets	8,378,000	5,897,000
Total current assets	132,505,000	122,878,000
Oil and gas properties, full cost method
Proved properties, net	1,959,951,000	1,965,347,000
Unproved properties, not being amortized	597,892,000	660,287,000
Other property and equipment, net	10,582,000	10,176,000
Total property and equipment, net	2,568,425,000	2,635,810,000
Other assets	20,909,000	19,616,000
Total Assets	2,721,839,000	2,778,304,000
Current liabilities
Accounts payable	113,651,000	74,558,000
Revenues and royalties payable	53,280,000	52,154,000
Accrued capital expenditures	117,934,000	119,452,000
Accrued interest	21,126,000	28,362,000
Derivative liabilities	145,520,000	57,121,000
Other current liabilities	52,020,000	41,175,000
Total current liabilities	503,531,000	372,822,000
Long-term debt	1,502,307,000	1,629,209,000
Asset retirement obligations	16,305,000	23,497,000
Derivative liabilities, noncurrent	87,933,000	112,332,000
Deferred income tax liabilities, noncurrent	4,164,000	3,635,000
Other liabilities	8,273,000	51,650,000
Liabilities	2,122,513,000	2,193,145,000
Preferred stock, $0.01 par value, 10,000,000 shares authorized; 200,000 issued and outstanding as of June 30, 2018 and 250,000 issued and outstanding as of December 31, 2017	172,858,000	214,262,000
Shareholders’ equity
Common stock, $0.01 par value, 180,000,000 shares authorized; 82,107,544 issued and outstanding as of June 30, 2018 and 81,454,621 issued and outstanding as of December 31, 2017	821,000	815,000
Additional paid-in capital	1,918,820,000	1,926,056,000
Accumulated deficit	(1,493,173,000)	(1,555,974,000)
Total shareholders’ equity	426,468,000	370,897,000
Total Liabilities and Shareholders’ Equity	$ 2,721,839,000	$ 2,778,304,000