Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of significant concentration risk

The following table identifies customers from whom the Company derived 10% or more of its oil and gas revenues during the years presented. Based on the availability of other customers, the Company does not believe the loss of any of these customers would have a significant effect on its business or financial condition.

	Year Ended December 31,
	2017	2016	2015
Superior Natural Gas	29%	14%	(a)
Shell Trading Company	24%	23%	18%
Laclede Energy Resources	(a)	17%	21%
BG Group	(a)	10%	10%
Unimark, LLC	(a)	(a)	17%

(a) Less than 10 percent