Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2017

Summary of Property and Equipment Including Oil and Natural Gas Properties

A summary of property and equipment including oil and natural gas properties is as follows (in thousands):

	March 31, 2017			December 31, 2016
Oil and natural gas properties:
Unproved	$	513,314		$	526,270
Proved		1,633,750			1,545,860
Gross oil and natural gas properties		2,147,064			2,072,130
Less accumulated depreciation depletion and amortization		(1,157,074	)		(1,131,378	)
Oil and natural gas properties, net		989,990			940,752
Other property and equipment		11,625			11,447
Less accumulated depreciation		(5,192	)		(4,699	)
Other property and equipment, net		6,433			6,748
Property and equipment, net	$	996,423		$	947,500

Changes in Company's Asset Retirement Obligation Liability

The following table sets forth the changes in the Company’s ARO liability for the three months ended March 31, 2017 (in thousands):

	Three Months Ended March 31, 2017
Asset retirement obligations, beginning of period	$	4,806
Additional liabilities incurred		124
Accretion		124
Asset retirement obligations, end of period	$	5,054

Summary of Reconciliation of Amounts in Previously Reported Consolidated Financial Statements

A reconciliation of the effects of the revision to amounts in the previously reported consolidated financial statements is as follows:

	As of December 31, 2016
	As Reported			Adjustment			As Adjusted
Balance Sheet
Accounts receivable	$	43,638		$	785		$	44,423
Total current assets		249,630			785			250,415
Total assets		1,197,859			785			1,198,644
Accrued liabilities		64,150			(9,106	)		55,044
Total current liabilities		140,625			(9,106	)		131,519
Total liabilities		651,143			(9,106	)		642,037
Accumulated deficit		(1,414,561	)		9,891			(1,404,670	)
Total stockholders' equity		546,716			9,891			556,607
Total liabilities and stockholders' equity		1,197,859			785			1,198,644

	As of December 31, 2016
	As Reported			Adjustment		As Adjusted
Statement of Stockholders' Equity
Accumulated deficit	$	(1,414,561	)	$	9,891	$	(1,404,670	)
Total stockholders' equity		546,716			9,891		556,607

	As of March 31, 2016
	As Reported			Adjustment			As Adjusted
Statement of Operations and Comprehensive Income    (Loss)
Production and ad valorem taxes	$	(2,284	)	$	4,847		$	2,563
Total operating expenses		95,367			4,847			100,214
Operating loss		(45,761	)		(4,847	)		(50,608	)
Loss before income taxes		(40,147	)		(4,847	)		(44,994	)
Net loss		(40,687	)		(4,847	)		(45,534	)
Basic and diluted loss per share	$	(0.18	)	$	(0.02	)	$	(0.20	)

	As of March 31, 2016
	As Reported			Adjustment			As Adjusted
Statement of Cash Flows
Net loss	$	(40,687	)	$	(4,847	)	$	(45,534	)
Accounts receivable	$	10,619		$	(172	)	$	10,447
Accounts payable and accrued liabilities		(32,476	)		5,019			(27,457	)

Accounts Receivable [Member] | Product Concentration Risk [Member]

Concentration Risk

The following table summarizes the Company’s concentration of receivables, net of allowances, by product or service as of March 31, 2017 and December 31, 2016 (in thousands):

	March 31, 2017		December 31, 2016
Receivables by product or service:
Sale of oil and natural gas and related products    and services	$	32,544	$	41,398
Joint interest owners		1,265		2,850
Derivatives		—		122
Other		14		53
Total	$	33,823	$	44,423