XML 101 R138.htm IDEA: XBRL DOCUMENT v2.4.0.8
Supplemental Information on Oil and Natural Gas Producing Activities - Costs Incurred in Oil and Natural Gas Property Acquisition, Exploration and Development (Parenthetical) (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]      
Exploration(1) $ 82,775 [1] $ 120,438 [1] $ 98,849 [1]
Development(2) 1,131,269 [2] 1,704,991 [2] 1,296,903 [2]
Seismic Costs
      
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]      
Exploration(1) 6,700 15,300 4,900
Contract Loss | Century Plant
      
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]      
Development(2)   $ 50,000 $ 25,000
[1] Includes seismic costs of $6.7 million, $15.3 million and $4.9 million for 2013, 2012 and 2011, respectively.
[2] Includes loss on the construction of the Century Plant of $50.0 million and $25.0 million for 2012 and 2011, respectively. See Note 11.