Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2016

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):

	June 30, 2016			December 31, 2015
Oil and natural gas properties:
Unproved	$	684,383		$	720,159
Proved		1,338,546			1,288,609
Gross oil and natural gas properties		2,022,929			2,008,768
Less accumulated depreciation depletion and amortization		(1,075,477	)		(1,022,771	)
Oil and natural gas properties, net		947,452			985,997
Other property and equipment		11,169			10,753
Less accumulated depreciation		(3,746	)		(2,782	)
Other property and equipment, net		7,423			7,971
Property and equipment, net	$	954,875		$	993,968

Changes in Company's Asset Retirement Obligation Liability

The following table sets forth the changes in the Company’s ARO liability for the six months ended June 30, 2016 (in thousands):

	Six Months Ended
	June 30, 2016
Asset retirement obligations, beginning of period	$	3,401
Additional liabilities incurred		63
Accretion		175
Asset retirement obligations, end of period	$	3,639

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 June 30, 2016 and December 31, 2015 (in thousands):

	June 30, 2016		December 31, 2015
Receivables by product or service:
Sale of oil and natural gas and related products and services	$	21,625	$	19,858
Joint interest owners		2,493		3,095
Derivatives		1,294		4,523
Miscellaneous other		73		—
Total	$	25,485	$	27,476