Annual report pursuant to Section 13 and 15(d)

Note 1 - Organization and Description of Business Segments (Details Textual)

v3.8.0.1
Note 1 - Organization and Description of Business Segments (Details Textual)
12 Months Ended
Dec. 31, 2017
a
Number of Operating Segments 2
West Texas [Member]  
Area of Land 890,000