Derivative Instruments and Hedging Activities (Derivatives Fair Value By Balance Sheet Location) (Details) (Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	$ 60	$ 1,924
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(1,108)	(241)
Derivative, Fair Value, Net	(1,048)	1,683
Current liabilities - Fair market value of derivatives [Member]
Derivative [Line Items]
Derivative Assets (Liability), Fair Value, Gross Asset Net	60
Derivative Assets (Liability), Fair Value, Gross Liability Net	1,036
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	8
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	1,088
Current liabilities - Fair market value of derivatives [Member] | Natural gas [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	60
Derivative Asset, Fair Value, Gross Liability		0
Derivative Liability, Fair Value, Gross Asset	0
Derivative Liability, Fair Value, Gross Liability		(125)
Derivative Assets (Liability), Fair Value, Gross Asset Net	60
Derivative Assets (Liability), Fair Value, Gross Liability Net		(125)
Non-current liabilities - Other long-term liabilities [Member]
Derivative [Line Items]
Derivative Assets (Liability), Fair Value, Gross Liability Net	(72)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(72)
Non-current liabilities - Other long-term liabilities [Member] | Natural gas [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Liability	0	0
Derivative Liability, Fair Value, Gross Liability	(72)	(116)
Derivative Assets (Liability), Fair Value, Gross Liability Net	(72)	(116)
Current assets - Fair market value of derivatives [Member] | Crude oil [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		1,674
Derivative Asset, Fair Value, Gross Liability	0
Derivative Liability, Fair Value, Gross Asset		0
Derivative Liability, Fair Value, Gross Liability	(1,036)
Derivative Assets (Liability), Fair Value, Gross Asset Net		1,674
Derivative Assets (Liability), Fair Value, Gross Liability Net	(1,036)
Non-current assets - Other long-term assets [Member]
Derivative [Line Items]
Derivative Assets (Liability), Fair Value, Gross Asset Net	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0
Non-current assets - Other long-term assets [Member] | Crude oil [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	250
Derivative Liability, Fair Value, Gross Asset	0	0
Derivative Assets (Liability), Fair Value, Gross Asset Net	$ 0	$ 250