Annual report pursuant to Section 13 and 15(d)

Supplemental Information On Oil And Gas Exploration And Production Activities (Narrative) (Details)

v2.4.0.6
Supplemental Information On Oil And Gas Exploration And Production Activities (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2012
MBoe
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2010
Oil and Gas Exploration and Production Industries Disclosures [Abstract]            
Prices per unit (usd per MMbls or MMcf) 2.76 91.32 96.19 4.12 76.16 4.38
Decrease in reserve during the period (12,564) (12,564)        
Decrease in reserves relating to change in estimates 442 442        
Future development costs estimated to be spent in 2013   $ 82,772        
Future development costs estimated to be spent in 2014   16,416        
Future development costs estimated to be spent in 2015   $ 4,335