Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

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, 2018			December 31, 2017
Oil and natural gas properties:
Unproved	$	537,958		$	459,549
Proved		1,973,468			1,896,081
Gross oil and natural gas properties		2,511,426			2,355,630
Less accumulated depreciation, depletion and amortization		(1,278,869	)		(1,248,200	)
Oil and natural gas properties, net		1,232,557			1,107,430
Other property and equipment		13,837			13,508
Less accumulated depreciation		(7,052	)		(6,566	)
Other property and equipment, net		6,785			6,942
Property and equipment, net	$	1,239,342		$	1,114,372

Summary of Revenue Disaggregated by Type

The following table illustrates the revenue disaggregated by type for the three months ended March 31, 2018 and 2017:

	Three Months Ended March 31,
	2018		2017
Revenues (in thousands)
Natural gas sales	$	58,483	$	61,420
NGL sales		19,743		17,063
Oil sales		31,958		20,949
Brokered natural gas and marketing revenue		8		2,431
Total revenues	$	110,192	$	101,863

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, 2018 (in thousands):

	Three Months Ended March 31, 2018
Asset retirement obligations, beginning of period	$	6,029
Additional liabilities incurred		85
Accretion		155
Asset retirement obligations, end of period	$	6,269

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, 2018 and December 31, 2017 (in thousands):

	March 31, 2018		December 31, 2017
Receivables by product or service:
Sale of oil and natural gas and related products    and services	$	51,298	$	52,908
Joint interest owners		60,263		23,154
Derivatives		1,628		1,528
Other		19		19
Total	$	113,208	$	77,609