Derivative Instruments (Commodity Derivatives) (Details)		3 Months Ended
		Mar. 31, 2016 USD ($) MMBTU $ / MMBTU	Dec. 31, 2015 USD ($)
Derivative [Line Items]
Fair Value Asset		$ 11,700	$ 13,400
Designated as Hedging Instrument | Natural Gas Put Options Production Period Ending December 31, 2016
Derivative [Line Items]
Volumes (MMBtu) | MMBTU	[1]	6,100
Average Fixed Price (per MMBtu) | $ / MMBTU	[1]	4.15
Fair Value Asset	[2]	$ 11,700

[1] “MMBtu” represents million British Thermal Units.

[2] Fair value based on forward NYMEX natural gas prices, as applicable.