Supplemental Crude Oil, Natural Gas and NGLs Information - Unaudited Supplemental Crude Oil, Natural Gas and NGLs Information - Unaudited (Tables)
 12 Months Ended
Dec. 31, 2013
Oil and Gas Exploration and Production Industries Disclosures [Abstract]  
Schedule of Prices Used to Estimate Natural Gas and Crude Oil Reserves [Table Text Block]
The following table presents the prices used to estimate this Partnership's reserves, by commodity:

 
 
Price Used to Estimate Reserves (1)
As of December 31,
 
Crude Oil (per Bbl)
 
Natural Gas (per Mcf)
 
NGLs (per Bbl)
2013
 
$
81.91

 
$
2.96

 
$
29.17

2012
 
87.32

 
2.18

 
28.27



(1)
The prices used to estimate reserves have been prepared in accordance with the SEC. Future estimated cash flows were based on a 12-month average price calculated as the unweighted arithmetic average of the prices on the first day of each month, January through December, applied to this Partnership's year-end estimated proved reserves. Prices for each of the two years were adjusted by field for Btu content, transportation and regional price differences; however, they were not adjusted to reflect the value of this Partnership's commodity derivatives.
Schedule of Proved Developed and Undeveloped Oil and Gas Reserve Quantities [Table Text Block]
The following table presents the changes in estimated quantities of this Partnership's reserves, all of which are located within the United States:
 
Natural Gas
 
NGLs
 
Crude Oil and Condensate
 
Crude Oil Equivalent
 
(MMcf)
 
(MBbl)
 
(MBbl)
 
(MBoe)
Proved Reserves:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Proved reserves, January 1, 2012
997

 
41

 
65

 
272

Revisions of previous estimates and reclassifications
(590
)
 
(25
)
 
(37
)
 
(160
)
Production
(71
)
 
(1
)
 
(2
)
 
(15
)
Proved reserves, December 31, 2012 (1)
336

 
15

 
26

 
97

 
 
 
 
 
 
 
 
Revisions of previous estimates and reclassifications
(121
)
 
(11
)
 
(10
)
 
(41
)
Dispositions (1)
(118
)
 
—

 
(1
)
 
(21
)
Production
(37
)
 
—

 
(2
)
 
(8
)
Proved reserves, December 31, 2013
60

 
4

 
13

 
27

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Proved Developed Reserves, as of:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
December 31, 2012
336

 
15

 
26

 
97

December 31, 2013
60

 
4

 
13

 
27

 
 
 
 
 
 
 
 

(1)
Includes estimated reserve data related to this Partnership's Piceance Basin assets. In June 2013, this Partnership's Piceance Basin crude oil and natural gas properties were divested. See Note 11, Divestiture and Discontinued Operations, for additional information regarding this divestiture. As of December 31, 2012, total proved reserves related to this Partnership's Piceance Basin include 144 MMcf of natural gas and 1 MBbl of crude oil, for an aggregate of 25 MBoe.
Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block]
Aggregate capitalized costs related to crude oil and natural gas development and production activities with applicable accumulated DD&A are presented below:
 
 As of December 31,
 
2013
 
2012 (1)
Leasehold costs
$
52,012

 
$
110,318

Development costs (2)
1,233,585

 
3,057,339

Crude oil and natural gas properties, successful efforts method, at cost
1,285,597

 
3,167,657

Less: Accumulated DD&A
(901,203
)
 
(2,270,162
)
Crude oil and natural gas properties, net
$
384,394

 
$
897,495