Employee Benefit Plans (Expected Benefit Payments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
2012	$ 529
2013	518
2014	510
2015	502
2016	496
2017-2021	2,384
Subsidy 2012	4
Subsidy 2013	3
Subsidy 2014	3
Subsidy 2015	3
Subsidy 2016	3
Subsidy 2017 - 2021	15
Qualified Pension Plans [Member]
2012	463
2013	451
2014	440
2015	434
2016	428
2017-2021	2,050
Non-Qualified Pension Plans [Member]
2012	17
2013	15
2014	17
2015	14
2016	13
2017-2021	64
Other Post-Retirement Benefit Plans [Member]
2012	49
2013	52
2014	53
2015	54
2016	55
2017-2021	$ 270

The amount of the aggregate benefits expected to be paid in the five fiscal years thereafter (the aggregate amount of benefits expected to be paid in years 6 through 10 after the date of the latest statement of financial position).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (f)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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Period Type:	instant

- Definition

The amount of the benefits expected to be paid in Year 5.

+ References

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- Definition

The amount of the benefits expected to be paid in Year 4.

+ References

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- Definition

The amount of the benefits expected to be paid in Year 1.

+ References

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- Definition

The amount of the benefits expected to be paid in Year 3.

+ References

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- Definition

The amount of the benefits expected to be paid in Year 2.

+ References

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- Definition

Aggregate amount for the next five fiscal years following the first five fiscal years (that is the aggregate of fiscal years six through ten) following the balance sheet date of the prescription drug subsidy receipts expected to be received.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 60

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph f

-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 FASB Staff Position (FSP)

-Number FAS106-2

-Paragraph 22

-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

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 5 after the balance sheet date.

+ References

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 4 after the balance sheet date.

+ References

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Amount of the prescription drug subsidy receipts expected to be received in Year 1 after the balance sheet date.

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Amount of the prescription drug subsidy receipts expected to be received in Year 3 after the balance sheet date.

+ References

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- Definition

Amount of the prescription drug subsidy receipts expected to be received in Year 2 after the balance sheet date.

+ References

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Namespace Prefix:	us-gaap_
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