|
Disclosures About Oil and Gas Producing Activities - Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Natural Gas Reserves (Detail) (USD $)
In Thousands, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Schedule Of Changes In Standardized Measure Of Discounted Future Net Cash Flows [Line Items] | |||
| Future cash flows | $ 4,920,231 | $ 3,772,633 | $ 1,804,477 |
| Future production costs | (1,220,403) | (1,012,044) | (499,321) |
| Future development costs | (1,025,193) | (625,994) | (259,005) |
| Future income tax expense | (692,528) | (583,961) | (282,628) |
| Future net cash flows | 1,982,107 | 1,550,634 | 763,523 |
| 10% annual discount for estimated timing of cash flows | (1,487,887) | (1,136,253) | (559,291) |
| Standardized measure of discounted future net cash flows | $ 494,220 | $ 414,381 | $ 204,232 |
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
This is the amount that is derived from using a discount rate of ten percent a year to reflect the timing of the future net cash flows relating to proved oil and gas reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Cash proceeds expected from future sale of oil and gas from proved reserves located in this geographic region. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The future cost of developing oil and gas from proved reserves located in this geographic region. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The estimated future income tax expenses that will be incurred based on the future income less future expenses derived from production and sale of proved oil and gas reserves in this geographic region. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
These amounts are the result of subtracting future development and production costs and future income tax expenses from future cash inflows for each geographic region where proved oil and gas reserves exist. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The future cost of producing oil and gas from proved reserves located in this geographic region. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
This amount is the future net cash flows less the computed discount. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|