Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS
Cash and cash equivalents	$ 17,224	$ 201,229
Accounts receivable	77,609	44,423
Assets held for sale	206	468
Other current assets	12,023	4,295
Total current assets	107,062	250,415
Oil and natural gas properties, successful efforts method:
Unproved properties	459,549	526,270
Proved oil and gas properties, net	647,881	414,482
Other property and equipment, net	6,942	6,748
Total property and equipment, net	1,114,372	947,500
OTHER NONCURRENT ASSETS
Other assets	2,093	729
TOTAL ASSETS	1,223,527	1,198,644
CURRENT LIABILITIES
Accounts payable	76,174	44,049
Accrued capital expenditures	10,658	11,083
Accrued liabilities	41,662	55,044
Accrued interest payable	21,100	21,098
Liabilities held for sale		245
Total current liabilities	149,594	131,519
NONCURRENT LIABILITIES
Debt, net of unamortized discount and debt issuance costs	495,021	492,278
Asset retirement obligations	6,029	4,806
Other liabilities	529	13,434
Total liabilities	651,173	642,037
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY
Preferred stock, 50,000,000 authorized, no shares issued and outstanding
Common stock, $0.01 par value, 1,000,000,000 authorized, 262,740,355 and 260,591,893 shares issued and outstanding, respectively	2,637	2,607
Additional paid in capital	1,967,958	1,958,731
Treasury stock, shares at cost; 992,315 and 72,704 shares, respectively	(2,096)	(61)
Accumulated deficit	(1,396,145)	(1,404,670)
Total stockholders' equity	572,354	556,607
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,223,527	$ 1,198,644