Pension and Other Postretirement Employee Benefit Plans (Details 7) (USD $) In Millions	12 Months Ended
Dec. 31, 2010
Effect of a one-percentage-point change in the assumed health care cost trend rate on the Firms total service and interest cost and accumulated postretirement benefit obligation
Effect on total service and interest cost, 1-Percentage-point increase	$ 2
Effect on total service and interest cost, 1-Percentage-point decrease	(2)
Effect on accumulated postretirement benefit obligation, 1-Percentage-point increase	36
Effect on accumulated postretirement benefit obligation, 1-Percentage-point decrease	$ (31)

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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. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.)

+ 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

+ Details

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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. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.)

+ 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

+ Details

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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. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.)

+ 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

+ Details

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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. (For purposes of this disclosure, all other assumptions shall be held constant, and the effects shall be measured based on the substantive plan that is the basis for the accounting.)

+ 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

+ Details

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