Pension and Postretirement Benefit Plans and Defined Contribution Plans - Pension Plans in Excess of Plan Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
U.S. Qualified Pension Plans [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets:
Fair value of plan assets	$ 12,706	$ 12,869
Accumulated benefit obligation	16,323	13,704
Pension plans with a projected benefit obligation in excess of plan assets:
Fair value of plan assets	12,706	12,869
Projected benefit obligation	16,575	13,976
U.S. Supplemental (Non-Qualified) Pension Plans [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	1,447	1,294
Pension plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	1,481	1,341
International Pension Plans [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets:
Fair value of plan assets	1,718	1,309
Accumulated benefit obligation	4,021	3,348
Pension plans with a projected benefit obligation in excess of plan assets:
Fair value of plan assets	1,999	2,499
Projected benefit obligation	$ 4,715	$ 4,883

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If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 55

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=34716465&loc=d3e4179-114921

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

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- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate benefit obligation for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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