Physical Delivery Contracts and Gas Derivatives (Details)	6 Months Ended
	Jun. 30, 2016 Volume
Contract 1 [Member] | Jul - Oct 2016 [Member]
Derivatives, Fair Value [Line Items]
Daily Volume (Dths per day)	1,000
Price	Index less $0.29
Contract 2 [Member] | Jul - Sep 2016 [Member]
Derivatives, Fair Value [Line Items]
Daily Volume (Dths per day)	611
Price	98% of Index less $0.23