XML 18 R33.htm IDEA: XBRL DOCUMENT v2.4.0.8
Properties and Equipment, Net (Details) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2014
Dec. 31, 2013
Property, Plant and Equipment [Abstract]    
Proved oil and gas properties $ 7,405,851 $ 6,362,570
Unproved oil and gas properties 354,882 375,428
Gathering and pipeline systems 240,705 239,958
Land, buildings and other equipment 105,143 94,243
Properties and equipment, gross, total 8,106,581 7,072,199
Accumulated depreciation, depletion and amortization (2,976,368) (2,525,972)
Properties and equipment, net $ 5,130,213 $ 4,546,227