Commitments and Contingencies - Future Minimum Lease Commitments Under Noncancellable Operating Leases with Initial or Remaining Terms of One Year or More (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
2015	$ 215
2016	151
2017	110
2018	86
2019	64
Thereafter	445
Total future lease commitments	$ 1,071

Commitments and Contingencies - Future Minimum Lease Commitments Under Noncancellable Operating Leases with Initial or Remaining Terms of One Year or More (Detail) (USD $)
In Millions, unless otherwise specified

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

$ 215us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent

2016

151us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears

2017

110us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears

2018

86us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears

2019

64us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears

Thereafter

445us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter

Total future lease commitments

$ 1,071us-gaap_OperatingLeasesFutureMinimumPaymentsDue

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

-Paragraph 40

-Subparagraph (Note 3)

-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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