Fair Value (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2011 Commodity contracts (net)	Dec. 31, 2010 Commodity contracts (net)	Dec. 31, 2011 Embedded derivatives in commodity contracts (net)	Dec. 31, 2010 Embedded derivatives in commodity contracts (net)	Dec. 31, 2010 Interest rate contracts	Dec. 31, 2010 Embedded derivative in debt contract
Derivative assets and liabilities classified by the Partnership within Level 3 of the valuation hierarchy
Fair value at beginning of period		$ (14,357,000)	$ (11,340,000)	$ (34,936,000)	$ (34,199,000)	$ 509,000	$ (190,000)
Total gain or (loss) (realized and unrealized) included in earnings		3,182,000	(11,093,000)	(30,827,000)	(11,792,000)	1,871,000	190,000
Purchases, sales, issuances and settlements (net)		8,210,000	8,076,000	11,859,000	11,055,000	(2,380,000)
Fair value at end of period		(2,965,000)	(14,357,000)	(53,904,000)	(34,936,000)
The amount of total gains or (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to contracts still held at end of period		6,241,000	(13,101,000)	(29,556,000)	(9,329,000)
Net book value of property plant and equipment that was written down to an estimated fair value of zero	5,200,000
Net book value of intangible assets that were written down to an estimated fair value of zero	700,000
Asset impairment charge	$ 5,855,000