Estimated Future Benefit Payments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
2014	$ 247
2015	259
2016	265
2017	271
2018	268
Years 2019 - 2023	1,435
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
2014	122
2015	123
2016	126
2017	129
2018	132
Years 2019 - 2023	717
Other Postretirement-Subsidy Receipts
Defined Benefit Plan Disclosure [Line Items]
2014	6
2015	7
2016	7
2017	8
2018	9
Years 2019 - 2023	$ 53

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Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ 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 (f)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

+ Details

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- Definition

Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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