Derivatives (Schedule of Derivatives Outstanding) (Details)	3 Months Ended
	Mar. 31, 2018 $ / Unit MMBTU bbl
Swap [Member] | Apr'18 - Sep'18 [Member] | Natural Gas [Member] | IF - NYMEX (HH) [Member]
Derivative [Line Items]
Weighted average price	2.985
Hedged volume (MMBtu/day) | MMBTU	40,000
Swap [Member] | Apr'18 - Sep'18 [Member] | Natural Gas Liquids [Member] | OPIS - Mont Belvieu [Member]
Derivative [Line Items]
Weighted average price	32.140	[1]
Hedged NGLs volume (Bbl/day) | bbl	1,500	[1]
Swap [Member] | Oct'18 [Member] | Natural Gas [Member] | IF - NYMEX (HH) [Member]
Derivative [Line Items]
Weighted average price	3.005
Hedged volume (MMBtu/day) | MMBTU	30,000
Swap [Member] | Nov'18 - Dec'18 [Member] | Natural Gas [Member] | IF - NYMEX (HH) [Member]
Derivative [Line Items]
Weighted average price	3.013
Hedged volume (MMBtu/day) | MMBTU	20,000
Swap [Member] | Apr'18 - Dec'18 [Member] | Crude Oil [Member] | WTI - NYMEX [Member]
Derivative [Line Items]
Weighted average price	53.520
Hedged volume (Bbl/day) | bbl	4,000
Basis swap [Member] | Nov'18 - Dec'18 [Member] | Natural Gas [Member] | IF - NYMEX (HH) [Member]
Derivative [Line Items]
Weighted average price	(0.208)
Hedged volume (MMBtu/day) | MMBTU	10,000
Basis swap [Member] | Apr'18 - Oct'18 [Member] | Natural Gas [Member] | NGPL Midcon [Member]
Derivative [Line Items]
Weighted average price	(0.190)
Hedged volume (MMBtu/day) | MMBTU	10,000
Basis swap [Member] | Apr'18 - Dec'18 [Member] | Natural Gas [Member] | NGPL Midcon [Member]
Derivative [Line Items]
Weighted average price	(0.568)
Hedged volume (MMBtu/day) | MMBTU	10,000
Basis swap [Member] | Apr'18 - Dec'18 [Member] | Natural Gas [Member] | PEPL [Member]
Derivative [Line Items]
Weighted average price	(0.678)
Hedged volume (MMBtu/day) | MMBTU	10,000
Basis swap [Member] | Jan'19 - Dec'19 [Member] | Natural Gas [Member] | NGPL Midcon [Member]
Derivative [Line Items]
Weighted average price	(0.625)
Hedged volume (MMBtu/day) | MMBTU	10,000
Basis swap [Member] | Jan'19 - Dec'19 [Member] | Natural Gas [Member] | NGPL Texok [Member]
Derivative [Line Items]
Weighted average price	(0.265)
Hedged volume (MMBtu/day) | MMBTU	30,000
Basis swap [Member] | Jan'19 - Dec'19 [Member] | Natural Gas [Member] | PEPL [Member]
Derivative [Line Items]
Weighted average price	(0.728)
Hedged volume (MMBtu/day) | MMBTU	10,000
Basis swap [Member] | Jan'20 - Dec'20 [Member] | Natural Gas [Member] | NGPL Texok [Member]
Derivative [Line Items]
Weighted average price	(0.280)
Hedged volume (MMBtu/day) | MMBTU	20,000
Collar [Member] | Apr'18 - Sep'18 [Member] | Natural Gas [Member] | IF - NYMEX (HH) [Member]
Derivative [Line Items]
Hedged volume (MMBtu/day) | MMBTU	30,000
Cap Price	2.97
Floor Price	2.67
Three-way collar [Member] | Apr'18 - Dec'18 [Member] | Crude Oil [Member] | WTI - NYMEX [Member]
Derivative [Line Items]
Hedged volume (Bbl/day) | bbl	2,000
Cap Price	56.08
Subfloor price	37.50
Floor Price	47.50
Three-way collar [Member] | Apr'18 - Dec'18 [Member] | Natural Gas [Member] | IF - NYMEX (HH) [Member]
Derivative [Line Items]
Hedged volume (MMBtu/day) | MMBTU	20,000
Cap Price	3.51
Subfloor price	2.50
Floor Price	3.00

[1] Type of NGLs involved is propane.