Derivative Instruments and Hedging Activities (Schedule of Outstanding Oil and Natural Gas Derivative Contracts) (Details) MMBTU in Thousands	1 Months Ended	9 Months Ended
	Nov. 02, 2016 $ / bbl MBbls	Sep. 30, 2016 MMBTU $ / MMBTU $ / bbl MBbls
Swap Contracts (WTI) for Remainder of 2016 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls		184
Average swap price		58.23
Swap Contracts Combined with Short Puts (WTI, Enhanced Swaps) for Full Year of 2017 [Member] | Crude Oil [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price		30.00
Swap Contracts Combined with Short Puts (WTI, Enhanced Swaps) for Full Year of 2017 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls		730
Strike price		44.50
Collar Contracts Combined with Short Puts (WTI, Three-Way Collars) For Remainder of 2016 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls		184
Collar Contracts Combined with Short Puts (WTI, Three-Way Collars) For Remainder of 2016 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price		65.00
Collar Contracts Combined with Short Puts (WTI, Three-Way Collars) For Remainder of 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price		55.00
Collar Contracts Combined with Short Puts (WTI, Three-Way Collars) For Remainder of 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Strike price		40.33
Collar Contracts (WTI, Two-Way Collars) for Remainder of 2016 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls		184
Collar Contracts (WTI, Two-Way Collars) for Remainder of 2016 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price		46.50
Collar Contracts (WTI, Two-Way Collars) for Remainder of 2016 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price		37.50
Collar Contracts (WTI, Two-Way Collars) for Full Year of 2017 [Member] | Crude Oil [Member]
Derivative [Line Items]
Total volume | MBbls		438
Collar Contracts (WTI, Two-Way Collars) for Full Year of 2017 [Member] | Crude Oil [Member] | Subsequent Event [Member]
Derivative [Line Items]
Total volume | MBbls	1,095
Collar Contracts (WTI, Two-Way Collars) for Full Year of 2017 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Strike price		59.05
Collar Contracts (WTI, Two-Way Collars) for Full Year of 2017 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member] | Subsequent Event [Member]
Derivative [Line Items]
Strike price	57.79
Collar Contracts (WTI, Two-Way Collars) for Full Year of 2017 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Strike price		47.50
Collar Contracts (WTI, Two-Way Collars) for Full Year of 2017 [Member] | Crude Oil [Member] | Put Option [Member] | Long [Member] | Subsequent Event [Member]
Derivative [Line Items]
Strike price	47.50
Collar Contracts Combined with Short Puts (Henry Hub, Three-Way Collars) for Remainder of 2017 [Member] | Natural Gas [Member]
Derivative [Line Items]
Total volume | MMBTU		1,460
Collar Contracts Combined with Short Puts (Henry Hub, Three-Way Collars) for Remainder of 2017 [Member] | Natural Gas [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Average swap price | $ / MMBTU		3.71
Collar Contracts Combined with Short Puts (Henry Hub, Three-Way Collars) for Remainder of 2017 [Member] | Natural Gas [Member] | Put Option [Member] | Long [Member]
Derivative [Line Items]
Average swap price | $ / MMBTU		3.00
Collar Contracts Combined with Short Puts (Henry Hub, Three-Way Collars) for Remainder of 2017 [Member] | Natural Gas [Member] | Put Option [Member] | Short [Member]
Derivative [Line Items]
Average swap price | $ / MMBTU		2.50
Short Call Option Contracts for Full Year of 2017 [Member] | Crude Oil [Member] | Call Option [Member] | Short [Member]
Derivative [Line Items]
Total volume | MBbls		670
Strike price		50.00
Swap Contracts (Midland Basis Differentials) for Remainder of 2016 [Member] | Crude Oil [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MBbls		368
Average swap price		0.17
Swap Contracts (Henry Hub) for Remainder of 2016 [Member] | Natural Gas [Member] | Swap [Member]
Derivative [Line Items]
Total volume | MMBTU		552
Average swap price | $ / MMBTU		2.52