Annual report pursuant to Section 13 and 15(d)

Acquisitions and Divestitures - Additional Information (Detail)

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Acquisitions and Divestitures - Additional Information (Detail) (USD $)
 1 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 1 Months Ended 3 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Jul. 11, 2013
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Oct. 17, 2013
Dec. 31, 2013
Callon Properties
Dec. 31, 2013
Callon Properties
Sep. 26, 2013
West Delta Area Block Twenty Nine
Oct. 05, 2012
Newfield Properties
acre
Dec. 31, 2012
Newfield Properties
Dec. 31, 2013
Newfield Properties
Dec. 31, 2012
Newfield Properties
May 15, 2012
South Timbalier 41
Aug. 10, 2011
Fairway Properties
Dec. 31, 2011
Opal Properties And Fairway Properties
Dec. 31, 2011
Opal Properties And Fairway Properties
Minimum
Dec. 31, 2011
Opal Properties And Fairway Properties
Maximum
May 11, 2011
Opal Properties
acre
Business Acquisition [Line Items]                                                    
Percentage of working interest include in producing interest                         15.00%                 64.30%        
Expenses associated with acquisition activities and transition activities                             $ 400,000         $ 600,000     $ 1,600,000      
Revenues   244,928,000 [1] 244,555,000 [1] 235,383,000 [1] 259,222,000 [1] 237,146,000 185,946,000 215,513,000 235,886,000 984,088,000 874,491,000 971,047,000   5,800,000       29,600,000         64,000,000      
Lease operating expenses                   270,839,000 232,260,000 219,206,000   1,300,000       5,400,000         25,500,000      
Depreciation, depletion, amortization and accretion                   451,529,000 356,232,000 328,786,000   2,400,000       11,900,000         20,500,000      
Income tax expense                   28,774,000 47,547,000 91,517,000   700,000       4,300,000         6,300,000      
Net income   (11,886,000) [1] 14,194,000 [1] 22,396,000 [1] 26,618,000 [1] 16,670,000 (1,471,000) 53,567,000 3,218,000 51,322,000 71,984,000 172,817,000   1,400,000       8,000,000         11,700,000      
Long-term debt, less current maturities   1,205,421,000       1,087,611,000       1,205,421,000 1,087,611,000     82,400,000 82,400,000     205,700,000   205,700,000     437,200,000      
Effective interest rate   8.40%               8.40%       2.00% 2.00%     7.70%   7.70%       2.60% 3.00%  
Federal statutory income tax rate                   35.00% 35.00% 35.00%     35.00%         35.00%     35.00%      
Reversal of asset retirement obligation 15,600,000                             3,900,000         4,000,000          
Adjustment for effective date to sell properties 4,300,000                                                  
Proceeds from sale of non-operating working interest                               16,500,000         30,500,000          
Number of federal offshore blocks                                 78                  
Leasehold interest acres acquired, gross                                 416,000                 24,500
Leasehold interest acres acquired, net                                 268,000                 21,900
Adjustments to purchase price                                     $ 200,000              
Percentage of non-operating working interest sold                                         40.00%          
[1] In January 2014, we identified that we had been receiving an erroneous million British thermal unit (“MMBtu”) conversion factor from a third party that had the effect of understating natural gas production at our Viosca Knoll 783 field (Tahoe).  The incorrect conversion factor had been used on all natural gas production from the field since we acquired it in 2011.  The use of the incorrect conversion factor did not affect revenues, operating cash flows or royalty payments to the federal government but did impact reported natural gas production and the calculation of depletion expense.  We performed an analysis of the information, assessing both quantitative and qualitative factors, and determined that the impact on our net income reported for prior annual periods, as well as the impact to our earnings trend, was not material to 2011 and 2012 results, thus the adjustment was recognized in the fourth quarter of 2013.  The fourth quarter of 2013 reflects a one-time increase in natural gas production volumes of 2.6 Bcf (with no corresponding increase in revenue) by using the correct conversion factor for the annual periods of 2011 and 2012, and the first three quarters of 2013, which increased DD&A by $7.1 million and decreased net income by $4.6 million.