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Supplemental Financial Information (Unaudited) (Tables) | 12 Months Ended
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Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract] |
Quarterly financial data | The following unaudited information shows selected items by quarter for the years 2012 and 2011:
| First Quarter |  | Second Quarter |  | * | Third Quarter |  | ** | Fourth Quarter |  | ***
| (In thousands, except per share amounts) |
2012 |  |  |  |  |  |  |
Operating revenues | $ | 852,807 |  | $ | 967,962 |  |  | $ | 1,173,518 |  |  | $ | 1,081,144 |  |
Operating expenses | 781,750 |  | 876,248 |  |  | 1,207,553 |  |  | 1,190,673 |  |
Operating income (loss) | 71,057 |  | 91,714 |  |  | (34,035 | ) |  | (109,529 | ) |
Income (loss) from continuing operations | 35,890 |  | 49,007 |  |  | (29,532 | ) |  | (69,686 | ) |
Income (loss) from discontinued operations, net of tax | (100 | ) | 5,106 |  |  | (139 | ) |  | 8,700 |  |
Net income (loss) | 35,790 |  | 54,113 |  |  | (29,671 | ) |  | (60,986 | ) |
Earnings (loss) per common share - basic: |  |  |  |  |  |  |  |  |  |  |
Earnings (loss) before discontinued operations | .19 |  | .26 |  |  | (.16 | ) |  | (.37 | ) |
Discontinued operations, net of tax | — |  | .03 |  |  | — |  |  | .05 |  |
Earnings (loss) per common share - basic | .19 |  | .29 |  |  | (.16 | ) |  | (.32 | ) |
Earnings (loss) per common share - diluted: |  |  |  |  |  |  |  |  |  |  |
Earnings (loss) before discontinued operations | .19 |  | .26 |  |  | (.16 | ) |  | (.37 | ) |
Discontinued operations, net of tax | — |  | .03 |  |  | — |  |  | .05 |  |
Earnings (loss) per common share - diluted | .19 |  | .29 |  |  | (.16 | ) |  | (.32 | ) |
Weighted average common shares outstanding: |  |  |  |  |  |  |  |  |  |  |
Basic | 188,811 |  | 188,831 |  |  | 188,831 |  |  | 188,831 |  |
Diluted | 189,182 |  | 189,107 |  |  | 188,831 |  |  | 188,831 |  |
2011 |  |  |  |  |  |  |  |  |  |  |
Operating revenues | $ | 901,805 |  | $ | 930,757 |  |  | $ | 1,152,181 |  |  | $ | 1,065,749 |  |
Operating expenses | 823,739 |  | 848,454 |  |  | 1,032,760 |  |  | 939,172 |  |
Operating income | 78,066 |  | 82,303 |  |  | 119,421 |  |  | 126,577 |  |
Income from continuing operations | 42,529 |  | 45,235 |  |  | 64,100 |  |  | 74,088 |  |
Income (loss) from discontinued operations, net of tax | 448 |  | (168 | ) |  | (126 | ) |  | (13,080 | ) |
Net income | 42,977 |  | 45,067 |  |  | 63,974 |  |  | 61,008 |  |
Earnings per common share - basic: |  |  |  |  |  |  |  |  |  |  |
Earnings before discontinued operations | .22 |  | .24 |  |  | .34 |  |  | .39 |  |
Discontinued operations, net of tax | .01 |  | — |  |  | — |  |  | (.07 | ) |
Earnings per common share - basic | .23 |  | .24 |  |  | .34 |  |  | .32 |  |
Earnings per common share - diluted: |  |  |  |  |  |  |  |  |  |  |
Earnings before discontinued operations | .22 |  | .24 |  |  | .34 |  |  | .39 |  |
Discontinued operations, net of tax | .01 |  | — |  |  | — |  |  | (.07 | ) |
Earnings per common share - diluted | .23 |  | .24 |  |  | .34 |  |  | .32 |  |
Weighted average common shares outstanding: |  |  |  |  |  |  |  |  |  |  |
Basic | 188,671 |  | 188,794 |  |  | 188,794 |  |  | 188,794 |  |
Diluted | 188,815 |  | 188,968 |  |  | 188,797 |  |  | 188,932 |  |
* 2012 reflects a net benefit of $15.0 million (after tax) related to natural gas gathering operations litigation and a net benefit largely related to estimated insurance recoveries related to the guarantee of a construction contract. For more information, see Note 19. ** 2012 reflects a $100.9 million after-tax noncash write-down of oil and natural gas properties. For more information, see Note 1. *** 2012 reflects a $145.9 million after-tax noncash write-down of oil and natural gas properties and the reversal of an arbitration charge of $13.0 million (after tax) related to a guarantee of a construction contract, which was partially offset by the reversal of estimated insurance recoveries, as previously discussed. 2011 reflects an arbitration charge of $13.0 million (after tax) related to a guarantee of a construction contract. For more information, see Notes 1 and 19, respectively.
Capital expenditures related to natural gas and oil producing activities [Table Text Block] | The following table sets forth capitalized costs and accumulated depreciation, depletion and amortization related to oil and natural gas producing activities at December 31:
| 2012 |  | 2011 |  | 2010 |
| (In thousands)
Subject to amortization | $ | 2,531,562 |  | $ | 2,345,114 |  | $ | 2,138,565 |
Not subject to amortization | 191,794 |  | 232,462 |  | 182,402 |
Total capitalized costs | 2,723,356 |  | 2,577,576 |  | 2,320,967 |
Less accumulated depreciation, depletion and amortization | 1,383,386 |  | 1,229,654 |  | 1,093,723 |
Net capitalized costs | $ | 1,339,970 |  | $ | 1,347,922 |  | $ | 1,227,244 |
Note: Net capitalized costs reflect noncash write-downs of the Company's oil and natural gas properties, as discussed in Note 1.
Cost incurred in oil and gas property acquisition, exploration, and development activities disclosure [Table Text Block] | Capital expenditures, including those not subject to amortization, related to oil and natural gas producing activities were as follows:
Years ended December 31, | 2012 |  | * | 2011 |  | * | 2010 |  | *
| (In thousands) |
Acquisitions: |  |  |  |  |  |  |  |  |
Proved properties | $ | 839 |  |  | $ | 3,999 |  |  | $ | 89,733 |  |
Unproved properties | 31,109 |  |  | 63,354 |  |  | 92,100 |  |
Exploration | 235,906 |  |  | 41,775 |  |  | 33,226 |  |
Development | 275,959 |  |  | 161,647 |  |  | 139,733 |  |
Total capital expenditures | $ | 543,813 |  |  | $ | 270,775 |  |  | $ | 354,792 |  |
* Excludes net additions/(reductions) to property, plant and equipment related to the recognition of future liabilities for asset retirement obligations associated with the plugging and abandonment of oil and natural gas wells, as discussed in Note 10, of $(200,000), $(1.8) million and $11.1 million for the years ended December 31, 2012, 2011 and 2010, respectively.
Results of operations for oil and gas producing activities disclosure [Table Text Block] | The following summary reflects income resulting from the Company's operations of oil and natural gas producing activities, excluding corporate overhead and financing costs:
Years ended December 31, | 2012 |  | 2011 |  | 2010 |
| (In thousands)
Revenues: |  |  |
Sales to affiliates | $ | 35,966 |  | $ | 93,713 |  | $ | 115,784 |
Sales to external customers | 412,651 |  | 359,873 |  | 318,565 |
Production costs | 134,795 |  | 140,606 |  | 127,403 |
Depreciation, depletion and amortization* | 157,078 |  | 139,539 |  | 127,266 |
Write-downs of oil and natural gas properties | 391,800 |  | — |  | — |
Pretax income (loss) | (235,056 | ) | 173,441 |  | 179,680 |
Income tax expense (benefit) | (88,612 | ) | 63,655 |  | 66,293 |
Results of operations for producing activities | $ | (146,444 | ) | $ | 109,786 |  | $ | 113,387 |
* Includes accretion of discount for asset retirement obligations of $3.3 million, $3.6 million and $3.2 million for the years ended December 31, 2012, 2011 and 2010, respectively, as discussed in Note 10.
Schedule of proved developed and undeveloped oil and gas reserve quantities [Table Text Block] | The changes in the Company's estimated quantities of proved oil, NGL and natural gas reserves for the year ended December 31, 2012, were as follows:
| Oil (MBbls) |  | NGL (MBbls) |  | Natural Gas (MMcf) |  | Total (MBOE) |
Proved developed and undeveloped reserves: |  |  |  |
Balance at beginning of year | 27,005 |  | 7,342 |  | 379,827 |  | 97,651 |
Production | (3,694 | ) | (828 | ) | (33,214 | ) | (10,058 | )
Extensions and discoveries | 9,874 |  | 1,817 |  | 18,386 |  | 14,756 |
Improved recovery | — |  | — |  | — |  | — |
Purchases of proved reserves | — |  | — |  | — |  | — |
Sales of proved reserves | (39 | ) | — |  | (2,307 | ) | (423 | )
Revisions of previous estimates | 307 |  | (1,178 | ) | (123,414 | ) | (21,440 | )
Balance at end of year | 33,453 |  | 7,153 |  | 239,278 |  | 80,486 |
Significant changes in proved reserves for the year ended December 31, 2012, include:
• | Extension and discoveries of 14.8 MMBOE primarily due to drilling activity at the Company's Bakken, South Texas, and Paradox properties
• | Revisions of previous estimates of (21.4) MMBOE, largely the result of lower natural gas prices resulting in a reduction of PDP and PUD reserves principally in the Company's Coalbed, Baker, Bowdoin, East Texas and Green River Basin natural gas properties
The changes in the Company's estimated quantities of proved oil, NGL and natural gas reserves for the year ended December 31, 2011, were as follows:
| Oil (MBbls) |  | NGL (MBbls) |  | Natural Gas (MMcf) |  | Total (MBOE) |
Proved developed and undeveloped reserves: |  |  |  |
Balance at beginning of year | 25,666 |  | 7,201 |  | 448,397 |  | 107,599 |
Production | (2,724 | ) | (776 | ) | (45,598 | ) | (11,099 | )
Extensions and discoveries | 4,717 |  | 1,421 |  | 28,221 |  | 10,842 |
Improved recovery | — |  | — |  | — |  | — |
Purchases of proved reserves | 223 |  | 16 |  | 54 |  | 247 |
Sales of proved reserves | — |  | — |  | — |  | — |
Revisions of previous estimates | (877 | ) | (520 | ) | (51,247 | ) | (9,938 | )
Balance at end of year | 27,005 |  | 7,342 |  | 379,827 |  | 97,651 |
Significant changes in proved reserves for the year ended December 31, 2011, include:
• | Extensions and discoveries of 10.8 MMBOE primarily due to drilling activity at the Company's Bakken and Big Horn properties
• | Revisions of previous estimates of (9.9) MMBOE, largely the result of a reduction in PUD reserves of 8.9 MMBOE resulting principally in the Company's Bowdoin, Baker, Coalbed, East Texas and Big Horn Basin properties. The remaining negative revisions were a reduction in PDP natural gas reserves.
The changes in the Company's estimated quantities of proved oil, NGL and natural gas reserves for the year ended December 31, 2010, were as follows:
| Oil (MBbls) |  | NGL (MBbls) |  | Natural Gas (MMcf) |  | Total (MBOE) |
Proved developed and undeveloped reserves: |  |  |  |
Balance at beginning of year | 25,930 |  | 8,286 |  | 448,425 |  | 108,954 |
Production | (2,767 | ) | (495 | ) | (50,391 | ) | (11,661 | )
Extensions and discoveries | 2,793 |  | 596 |  | 36,191 |  | 9,421 |
Improved recovery | — |  | — |  | — |  | — |
Purchases of proved reserves | 911 |  | 68 |  | 55,119 |  | 10,165 |
Sales of proved reserves | (18 | ) | — |  | (92 | ) | (34 | )
Revisions of previous estimates | (1,183 | ) | (1,254 | ) | (40,855 | ) | (9,246 | )
Balance at end of year | 25,666 |  | 7,201 |  | 448,397 |  | 107,599 |
Significant changes in proved reserves for the year ended December 31, 2010, include:
• | Extensions and discoveries of 9.4 MMBOE primarily due to drilling activity at the Company's Bakken, Baker, Bowdoin and east Texas properties
• | Purchases of proved reserves of 10.2 MMBOE as a result of the Company's acquisition of natural gas properties in the Green River Basin in Wyoming, as discussed in Note 2
• | Revisions of previous estimates of (9.2) MMBOE largely the result of negative performance revisions resulting primarily from new information gained from production history and developmental drilling activity in the Company's Bowdoin, south Texas, Baker and east Texas properties and removal of PUD reserves due to the five-year limitation rule, partially offset by positive revisions due to increased oil and natural gas prices
The following table summarizes the breakdown of the Company's proved reserves between proved developed and PUD reserves at December 31:
| 2012 |  | 2011 |  | 2010 |
Proved developed reserves: |  |  |
Oil (MBbls) | 27,412 |  | 23,653 |  | 22,352 |
NGL (MBbls) | 5,342 |  | 5,225 |  | 4,234 |
Natural Gas (MMcf) | 218,259 |  | 303,495 |  | 334,911 |
Total (MBOE) | 69,131 |  | 79,460 |  | 82,404 |
PUD reserves: |  |  |  |  |  |
Oil (MBbls) | 6,041 |  | 3,352 |  | 3,314 |
NGL (MBbls) | 1,811 |  | 2,117 |  | 2,967 |
Natural Gas (MMcf) | 21,019 |  | 76,332 |  | 113,486 |
Total (MBOE) | 11,355 |  | 18,191 |  | 25,195 |
Total proved reserves: |  |  |  |  |  |
Oil (MBbls) | 33,453 |  | 27,005 |  | 25,666 |
NGL (MBbls) | 7,153 |  | 7,342 |  | 7,201 |
Natural Gas (MMcf) | 239,278 |  | 379,827 |  | 448,397 |
Total (MBOE) | 80,486 |  | 97,651 |  | 107,599 |
Standardized measure of discounted future cash flows relating to proved reserves disclosure [Table Text Block] | The standardized measure of the Company's estimated discounted future net cash flows of total proved reserves associated with its various oil and natural gas interests at December 31 was as follows:
| 2012 |  | 2011 |  | 2010 |
| (In thousands)
Future cash inflows | $ | 3,696,200 |  | $ | 4,188,000 |  | $ | 3,790,700 |
Future production costs | 1,536,500 |  | 1,560,300 |  | 1,393,000 |
Future development costs | 301,600 |  | 285,300 |  | 312,500 |
Future net cash flows before income taxes | 1,858,100 |  | 2,342,400 |  | 2,085,200 |
Future income tax expense | 304,900 |  | 531,100 |  | 432,800 |
Future net cash flows | 1,553,200 |  | 1,811,300 |  | 1,652,400 |
10% annual discount for estimated timing of cash flows | 669,800 |  | 832,500 |  | 756,300 |
Discounted future net cash flows relating to proved oil, NGL and natural gas reserves | $ | 883,400 |  | $ | 978,800 |  | $ | 896,100 |
The following are the sources of change in the standardized measure of discounted future net cash flows by year:
| 2012 |  | 2011 |  | 2010 |
| (In thousands)
Beginning of year | $ | 978,800 |  | $ | 896,100 |  | $ | 658,800 |
Net revenues from production | (280,800 | ) | (301,500 | ) | (270,000 | )
Net change in sales prices and production costs related to future production | (406,300 | ) | 82,300 |  | 362,400 |
Extensions and discoveries, net of future production-related costs | 355,300 |  | 226,300 |  | 130,500 |
Improved recovery, net of future production-related costs | — |  | — |  | — |
Purchases of proved reserves, net of future production-related costs | — |  | 9,500 |  | 99,800 |
Sales of proved reserves | (2,600 | ) | — |  | (500 | )
Changes in estimated future development costs | 37,600 |  | 51,100 |  | 34,100 |
Development costs incurred during the current year | 77,700 |  | 56,300 |  | 43,100 |
Accretion of discount | 121,400 |  | 105,000 |  | 76,500 |
Net change in income taxes | 110,000 |  | (55,800 | ) | (103,300 | )
Revisions of previous estimates | (100,700 | ) | (92,900 | ) | (132,000 | )
Other | (7,000 | ) | 2,400 |  | (3,300 | )
Net change | (95,400 | ) | 82,700 |  | 237,300 |
End of year | $ | 883,400 |  | $ | 978,800 |  | $ | 896,100 |

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- Definition Tabular disclosure of the future net cash flows relating to proved oil and gas reserves and oil and gas subject to purchase under long-term agreements in which the enterprise participates in the operation of the properties on which the oil and gas is located or otherwise serves as the producer. This information is presented in aggregate and for each geographic area for which reserve quantities are disclosed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62455-109447 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 35 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62500-109447 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 36 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62536-109447 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 32 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62476-109447 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62424-109447 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e62479-109447 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 19 -Paragraph 59Y, 59Z, 59AA, 59BB, 59CC -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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