| **Postretirement Benefits Assumptions (Details) (USD $)In Millions, unless otherwise specified**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 | 12 Months Ended | 1 Months Ended | 3 Months Ended | 12 Months Ended | 1 Months Ended | 5 Months Ended | 12 Months Ended |
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| **Weighted Average Assumptions Used in Determining Benefit Obligation [Abstract]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |            |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
| Discount rate used to determine present value of benefit obligation at end of year                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |            | 4.20%          |                |            |           | 4.80%          |                 |   |  | 4.20% |  |   |   | 4.60% |  |   |  |   |
| Expected rate of increase in future compensation levels                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |            | 3.50%          |                |            |           | 3.50%          |                 |   |  | 0.00% |  |   |   | 0.00% |  |   |  |   |
| **Weighted Average Assumptions Used in Determining Net Postretirement Benefits Expense [Abstract]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |            |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
| Discount rate                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |            | 4.80%          | [1]            | 6.50%           | 8.30%          | 5.40%          | [1]             | 7.60% | [1] | 4.60% | [1] | 5.60% | 5.50% | 5.60% | [1] | 8.40% | [1] | 7.60% |
| Expected long-term rate of return on plan assets                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |            | 8.50%          |                |            |           | 8.50%          |                 | 9.00% |  | 8.50% |  |   |   | 8.50% |  | 9.00% |  |   |
| Expected rate of increase in future compensation levels                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |            | 3.50%          |                |            |           | 3.50%          |                 | 3.50% |  | 0.00% |  |   |   | 0.00% |  | 0.00% |  |   |
| **Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |            |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
| Effect of One Percentage Point Increase on Service and Interest Cost Components                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | $ 5             |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
| Effect of One Percentage Point Decrease on Service and Interest Cost Components                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  | (8)             |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
| Effect of One Percentage Point Increase on Postretirement Benefit Obligation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | 192             |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
| Effect of One Percentage Point Decrease on Postretirement Benefit Obligation                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     | $ (201)         |           |                |            |           |           |                 |   |  |   |  |   |   |   |  |   |  |   |
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| [1]In 2009 for pension benefits, the weighted average discount rate used to compute the expense for the period of November 1, 2008 through January 31, 2009 was 8.3%. Due to a plan remeasurement at January 31, 2009 at a rate of 6.5%, the weighted average discount rate for the full fiscal year 2009 was 7.6%. In 2010 for health and life insurance benefits, the weighted average discount rate used to compute the expense for the period of November 1, 2009 through March 31, 2010 was 5.5%. Due to a plan remeasurement at March 31, 2010 at a rate of 5.6%, the weighted average discount rate for the full fiscal year 2010 was 5.6%. |

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| - Definition
The interest rate used to adjust for the time value of money for the plan.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Expected rate of compensation increases (for pay-related plans).
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The interest rate used to adjust for the time value of money.
+ References
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| - Definition
An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 -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.Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph j -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.Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Expected Long-Term Rate of Return on Plan Assets -URI http://asc.fasb.org/extlink&oid=6512013 -Topic 715 -SubTopic 30
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Expected rate of compensation increases (for pay-related plans).
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m -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.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (m) -URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920
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| - Definition
The effect of a one-percentage- point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m -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.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (m) -URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph m -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.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (m) -URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.
+ References
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