DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES (Fair Values of Expected Cash Flows of Commodity Based Swaps and Physical Contracts) (Details) $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2015 USD ($) bbl MMBTU $ / bbl $ / MMBTU	Dec. 31, 2014 USD ($)
Fair Value
Asset		$ 180.8	$ 279.1
Liability	[1]	$ (417.3)	$ (440.0)
Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	1,558,292
Fair Value
Asset	[3]	$ 0.1
Liability	[3]	$ (0.2)	$ (0.7)
Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	901,000
Fair Value
Asset	[3]	$ 0.1
Liability	[3]	$ (3.8)	$ (6.8)
Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	504,000
Fair Value
Asset	[3]
Liability	[3]	$ (12.0)	$ (27.4)
Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	2,550,938
Fair Value
Asset	[3]	$ 0.5	$ 3.7
Liability	[3]
Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	1,720,600
Fair Value
Asset	[3]	$ 17.4	$ 39.2
Liability	[3]	$ (0.3)
Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	961,064
Fair Value
Asset	[3]	$ 29.5	$ 65.0
Liability	[3]
Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	47,491,500
Fair Value
Asset	[3]	$ 1.5	$ 1.5
Liability	[3]	$ (1.2)	$ (1.7)
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	106,700
Fair Value
Asset	[3]
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	767,000
Fair Value
Asset	[3]	$ 0.2
Liability	[3]	$ (0.1)	$ (3.6)
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	33,400
Fair Value
Asset	[3]
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	209,936
Fair Value
Asset	[3]
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	3,396,447
Fair Value
Asset	[3]	$ 4.9	$ 19.8
Liability	[3]	$ (1.2)
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	107,000
Fair Value
Asset	[3]		$ 0.5
Liability	[3]	$ (0.1)
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	136,481,498
Fair Value
Asset	[3]	$ 1.1	$ 2.2
Liability	[3]	$ (0.2)	(1.0)
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	8,585,747
Fair Value
Asset	[3]	$ 5.6	3.7
Liability	[3]	$ (0.6)	(1.0)
Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	911,227
Fair Value
Asset	[3]	$ 1.1	0.3
Liability	[3]	$ (1.4)	$ (1.7)
Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	363,514
Fair Value
Asset	[3]
Liability	[3]	$ (0.2)	$ (0.1)
Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	823,500
Fair Value
Asset	[3]
Liability	[3]	$ (1.8)
Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	415,950
Fair Value
Asset	[3]
Liability	[3]	$ (8.6)	$ (8.1)
Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	1,898,100
Fair Value
Asset	[3]	$ 0.1
Liability	[3]	$ (0.1)
Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	883,500
Fair Value
Asset	[3]	$ 9.2	$ 9.3
Liability	[3]
Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	769,270
Fair Value
Asset	[3]	$ 9.5	$ 9.1
Liability	[3]	$ (0.1)
Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	50,739,000
Fair Value
Asset	[3]	$ 1.6	$ 0.5
Liability	[3]	$ (1.0)	$ (0.3)
Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]
Fair Value
Asset	[3]
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	63,850
Fair Value
Asset	[3]
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	38,963
Fair Value
Asset	[3]	$ 0.1
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	99,005,643
Fair Value
Asset	[3]	$ 0.8	$ 0.7
Liability	[3]		$ (0.4)
Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	9,676,152
Fair Value
Asset	[3]	$ 1.8
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	30,400
Fair Value
Asset	[3]	$ 0.1
Liability	[3]
Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	24,030
Fair Value
Asset	[3]
Liability	[3]
Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	547,500
Fair Value
Asset	[3]
Liability	[3]	$ (1.5)
Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	547,500
Fair Value
Asset	[3]
Liability	[3]	$ (1.7)
Swaps - Portion of Contracts Maturing in 2017 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Notional | bbl	[2]	547,500
Fair Value
Asset	[3]	$ 0.6	$ 0.7
Liability	[3]	$ (0.3)
Swaps - Portion of Contracts Maturing in 2017 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Notional | bbl	[2]	547,500
Fair Value
Asset	[3]	$ 2.1	$ 0.8
Liability	[3]	$ (0.4)
Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	5,910,000
Fair Value
Asset	[3]	$ 0.2
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	28,097,550
Fair Value
Asset	[3]	$ 0.2	$ 0.2
Liability	[3]		$ (0.1)
Physical Contracts - Portion of Contracts Maturing in 2018 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	5,787,810
Fair Value
Asset	[3]	$ 0.1
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2019 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	2,187,810
Fair Value
Asset	[3]
Liability	[3]
Physical Contracts - Portion of Contracts Maturing in 2020 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Notional | MMBTU	[2]	359,640
Fair Value
Asset	[3]
Liability	[3]
Swap [Member]
Fair Value
Credit valuation adjustments		$ 0.0	$ (0.5)
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.77
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	32.48
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	60.30
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.00
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	38.80
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	91.18
Receive [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.73
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.66
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	11.59
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	59.60
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.81
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	21.07
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	59.58
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.80
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	23.33
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	58.61
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.83
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	28.45
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	62.01
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.21
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	38.48
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	74.36
Receive [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.01
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.11
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	32.99
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.13
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	21.94
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	61.65
Receive [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.27
Receive [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	23.14
Receive [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	63.62
Receive [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	23.59
Receive [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	66.78
Receive [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.24
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.39
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2018 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.57
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2019 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.54
Receive [Member] | Physical Contracts - Portion of Contracts Maturing in 2020 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.86
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.83
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	36.64
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	84.19
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.83
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	28.84
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	60.31
Pay [Member] | Swaps - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.72
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.70
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	11.40
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	59.45
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.73
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	19.97
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	59.69
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.79
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	22.75
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2015 - Receive Variable/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	58.91
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.41
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	30.70
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	82.69
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.24
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	28.05
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	62.04
Pay [Member] | Swaps - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	2.99
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.06
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	31.84
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.12
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	21.76
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2016 - Receive Variable/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	59.30
Pay [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.48
Pay [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	25.86
Pay [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Fixed - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	66.72
Pay [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Fixed/Pay Variable - NGL [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	23.14
Pay [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Fixed/Pay Variable - Crude Oil [Member]
Derivative [Line Items]
Wtd. Average Price | $ / bbl	[4]	63.62
Pay [Member] | Swaps - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.20
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2017 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.38
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2018 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.56
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2019 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.51
Pay [Member] | Physical Contracts - Portion of Contracts Maturing in 2020 - Receive Variable/Pay Variable - Natural Gas [Member]
Derivative [Line Items]
Wtd. Average Price | $ / MMBTU	[4]	3.83

[1] Includes $11.5 million and $28.4 million of cash collateral at June 30, 2015 and December 31, 2014, respectively.

[2] Volumes of natural gas are measured in MMBtu, whereas volumes of NGL and crude oil are measured in Bbl.

[3] The fair value is determined based on quoted market prices at June 30, 2015 and December 31, 2014, respectively, discounted using the swap rate for the respective periods to consider the time value of money. Fair values exclude credit valuation adjustment losses of approximately $0.0 million and $0.5 million at June 30, 2015 and December 31, 2014, respectively, as well as cash collateral received.

[4] Weighted average prices received and paid are in $/MMBtu for natural gas and $/Bbl for NGL and crude oil.