Employee Retirement Plans - Benefits Expected to be Paid (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Qualified Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
2013	$ 44
2014	45
2015	46
2016	47
2017	49
2018-2022	265
Non-Qualified Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
2013	12
2014	12
2015	12
2016	12
2017	12
2018-2022	$ 58

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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=21915506&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

+ Details

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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

+ Details

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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

+ Details

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- Definition

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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- Definition

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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