Derivatives (Derivatives Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013 gal
Short Contracts [Member] | Liquids [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(50,400,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	$ 428
Long Contracts [Member] | Liquids [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(50,400,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	(537)
Cash Flow Liquid Swap [Member] | Short Contracts [Member] | Liquids [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(8,567,000)
Cash Flow Hedges Derivative Instruments at Fair Value, Net, Total	(696)
Swing Swap [Member] | Short Contracts [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(78,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	2
Swing Swap [Member] | Long Contracts [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(1,457,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	(14)
Physical Offset To Swing Swap [Member] | Short Contracts [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(1,147,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	0
Physical Offset To Swing Swap [Member] | Long Contracts [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(78,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	0
Processing Margin Hedges [Member] | Short Contracts [Member] | Liquids [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(2,662,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	(270)
Processing Margin Hedges [Member] | Long Contracts [Member] | Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(291,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	40
Storage Swap [Member] | Short Contracts [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(100,000)
Derivative Non Designated Assets (Liabilities), at Fair Value, Net	$ (18)