Fair Value Measurements (Tables)
 6 Months Ended
Jun. 30, 2013
Fair Value Disclosures [Abstract]  
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis
The following table presents the Partnership's assets and liabilities that are measured at fair value as of June 30, 2013:
 
 
Fair Value Measurements at the End of the Reporting Period Using
 
 
  
 
Quoted Prices in
Active  Markets
for Identical
Assets
(Level 1)
 
Significant
Other
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Fair Value at June 30, 2013
 
 
(in thousands)
Recurring fair value measurements
 
 
 
 
 
 
 
 
Assets:
 
 
 
 
 
 
 
 
Commodity derivatives
 
$
—

 
$
14,568

 
$
—

 
$
14,568

Liabilities:
 
 
 
 
 
 
 
 
Commodity derivatives
 
—

 
6,453

 
—

 
6,453

Total recurring fair value measurements
 
$
—

 
$
8,115

 
$
—

 
$
8,115
Schedule of Fair Value, by Balance Sheet Grouping
The carrying values and fair values of financial instruments that are not recorded at fair value in the accompanying consolidated balance sheets as of June 30, 2013 and December 31, 2012 are as follows:
 
 
June 30, 2013
 
December 31, 2012
  
 
Carrying
Value
 
Fair
Value
 
Carrying
Value
 
Fair
Value
 
 
(in thousands)
Credit facility
 
$
176,000

 
$
169,216

 
$
126,000

 
$
123,635