Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets
Cash	$ 6,254	$ 34,642
Accounts receivable, net
Oil and gas sales	24,557	26,568
Joint interest owners	9,032	5,267
Other	7,205	6,061
Commodity derivative assets	39,823	24,100
Other current assets	11,381	2,684
Assets held for sale	3,455
Total current assets	101,707	99,322
Assets held for sale, net	64,200
Oil and gas properties, net, at cost under the successful efforts method	1,545,991	1,743,588
Other property, plant and equipment, net	2,812	2,996
Commodity derivative assets	5,914	34,744
Other assets	5,395	6,050
Total assets	1,726,019	1,886,700
Current liabilities
Trade accounts payable	56,053	36,527
Oil and gas sales payable	22,301	28,339
Accrued liabilities	19,571	25,707
Commodity derivative liabilities	3,036	14,650
Other current liabilities	8,099	2,584
Liabilities related to assets held for sale	7,472
Disposal Group, Including Discontinued Operation, Liabilities, Current	7,472
Total current liabilities	116,532	107,807
Liabilities related to assets held for sale	1,143
Long-term debt	728,163	724,009
Deferred revenue	6,106	7,049
Commodity derivative liabilities	123	1,209
Asset retirement obligations	19,061	19,458
Liability under tax receivable agreement	11,807	43,045
Other liabilities	902	792
Deferred tax liabilities	2,911	2,905
Total liabilities	886,748	906,274
Commitments and contingencies (Note 14)
Mezzanine equity
Series A preferred stock, $0.001 par value; 1,840,000 shares issued and outstanding at June 30, 2017 and December 31, 2016	89,288	88,975
Stockholders' equity
Treasury stock, at cost: 22,602 shares at June 30, 2017 and December 31, 2016	(358)	(358)
Additional paid-in-capital	477,390	447,137
Retained (deficit) / earnings	(121,477)	(8,652)
Stockholders' equity	355,652	438,214
Non-controlling interest	394,331	453,237
Total stockholders' equity	749,983	891,451
Total liabilities and stockholders' equity	1,726,019	1,886,700
Class A common stock
Stockholders' equity
Common stock	67	57
Class B common stock
Stockholders' equity
Common stock	$ 30	$ 30