Net gain (loss) from the increase (decrease) in fair value of derivative instrument not designated as hedging instrument.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph b(1)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624171-113959

Name:	us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Derivative Financial Instruments (Derivatives And Hedging-Overall-Subsequent Measurement) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
NYMEX commodity contracts	$ 27,606	$ (8,466)	$ (7,895)	$ 8,366
NYMEX Commodity Contracts [Member] \| Operating Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
NYMEX commodity contracts	(923)		598
NYMEX Commodity Contracts [Member] \| Product Sales Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
NYMEX commodity contracts	28,579	(8,466)	(7,604)	8,366
Butane Price Swap Purchase Contracts [Member] \| Product Purchases [Member]
Derivative Instruments, Gain (Loss) [Line Items]
NYMEX commodity contracts	$ (50)		$ (889)