Fair Value (Details 4) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Commodity contracts
Derivative assets and liabilities classified by the Partnership within Level 3 of the valuation hierarchy
Fair value at beginning of period	$ 4,778	$ (2,092)	$ 3,840	$ (5,460)
Total gain (loss) (realized and unrealized) included in earnings	11,388	5,626	18,311	1,387
Settlements	(7,859)	(380)	(13,844)	7,227
Fair value at end of period	8,307	3,154	8,307	3,154
The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to contracts still held at end of period	6,276	4,109	8,307	3,926
Embedded derivatives in commodity contracts
Derivative assets and liabilities classified by the Partnership within Level 3 of the valuation hierarchy
Fair value at beginning of period	11,736	(42,831)	18,776	(35,032)
Total gain (loss) (realized and unrealized) included in earnings	7,671	10,715	(2,527)	(1,352)
Settlements	1,042	2,203	4,200	6,471
Fair value at end of period	20,449	(29,913)	20,449	(29,913)
The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to contracts still held at end of period	$ 10,103	$ 11,609	$ 2,943	$ 716