Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments (Narrative) (Details)

v3.4.0.3
Derivative Instruments (Narrative) (Details) - January 2017 - December 2017
Mar. 31, 2016
MMBTU / d
$ / MMBTU
Derivative [Line Items]  
Daily Volume | MMBTU / d 30,000
Weighted Average Price (in usd per MMBtu) | $ / MMBTU 3.33
Short  
Derivative [Line Items]  
Daily Volume | MMBTU / d 30,000
Weighted Average Price (in usd per MMBtu) | $ / MMBTU 3.33