Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments (Narrative) (Details)

v3.7.0.1
Derivative Instruments (Narrative) (Details)
3 Months Ended
Mar. 31, 2017
MMBTU / d
$ / MMBTU
Derivative [Line Items]  
Derivative, extension option term 12 months
2018  
Derivative [Line Items]  
Daily Volume | MMBTU / d 30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU 3.36
2018 | Short  
Derivative [Line Items]  
Daily Volume | MMBTU / d 30,000
Weighted average price (in usd per MMB/Bblstu) | $ / MMBTU 3.36