XML 65 R49.htm IDEA: XBRL DOCUMENT v3.3.1.900
Segment Information and Major Customers - Segment Information by Major Customers (Detail) - Sales [Member]
12 Months Ended
Dec. 31, 2015
Plains All American Inc., Oil Purchasers [Member]  
Revenue, Major Customer [Line Items]  
Revenue by major customers 43.55%
Sunoco Inc., Oil Purchasers [Member]  
Revenue, Major Customer [Line Items]  
Revenue by major customers 24.92%
Targa Pipeline Mid-Continent [Member]  
Revenue, Major Customer [Line Items]  
Revenue by major customers 23.27%
Primexx Energy Corporation [Member]  
Revenue, Major Customer [Line Items]  
Revenue by major customers 10.90%