| **Benefit Plans**                                     | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
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| **Compensation and Retirement Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Benefit Plans                                         | Benefit PlansThe components of net periodic cost (benefit) are presented in the following table.Net Periodic Cost (Benefit)Periods ended September 30Three Months Nine Months(In millions)2011 2010 2011 2010Pension cost       Service cost$3 $5 $10 $13Interest cost on projected benefit obligation37 38 110 112Expected return on plan assets(44) (41) (130) (122)Amortization of net actuarial loss7 6 19 18Net periodic pension cost$3 $8 $9 $21        Postretirement benefit       Service cost$— $— $— $1Interest cost on projected benefit obligation1 2 3 6Amortization of prior service credit(5) (4) (14) (12)Amortization of net actuarial loss— — — 1Net periodic postretirement benefit$(4) $(2) $(11) $(4) |

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| - Definition
The entire disclosure for pension and other postretirement benefits.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -URI http://asc.fasb.org/topic&trid=2235017Reference 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 158 -Paragraph 7, 21, 22 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  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