| **Pension and Postretirement Benefit Plans and Defined Contribution Plans - Funded Status Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions**                                              | Dec. 31, 2015 | Dec. 31, 2014 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| U.S. Qualified Pension Plans [Member]                                                                                                                                                                               |               |          |   |
| **Defined Benefit Plan Disclosure [Line Items]**                                                                                                                                                                    |               |          |   |
| Noncurrent assets                                                                                                                                                                                                   | [1]           | $ 0           | $ 0 |
| Current liabilities                                                                                                                                                                                                 | [2]           | 0             | 0 |
| Noncurrent liabilities                                                                                                                                                                                              | [3]           | (3,292)       | (3,869) |
| Funded status                                                                                                                                                                                                       |               | (3,292)       | (3,869) |
| U.S. Supplemental (Non-Qualified) Pension Plans [Member]                                                                                                                                                            |               |          |   |
| **Defined Benefit Plan Disclosure [Line Items]**                                                                                                                                                                    |               |          |   |
| Noncurrent assets                                                                                                                                                                                                   | [1]           | 0             | 0 |
| Current liabilities                                                                                                                                                                                                 | [2]           | (126)         | (136) |
| Noncurrent liabilities                                                                                                                                                                                              | [3]           | (1,216)       | (1,345) |
| Funded status                                                                                                                                                                                                       |               | (1,343)       | (1,481) |
| International Pension Plans [Member]                                                                                                                                                                                |               |          |   |
| **Defined Benefit Plan Disclosure [Line Items]**                                                                                                                                                                    |               |          |   |
| Noncurrent assets                                                                                                                                                                                                   | [1]           | 572           | 509 |
| Current liabilities                                                                                                                                                                                                 | [2]           | (25)          | (45) |
| Noncurrent liabilities                                                                                                                                                                                              | [3]           | (1,801)       | (2,671) |
| Funded status                                                                                                                                                                                                       |               | (1,255)       | (2,208) |
| Postretirement Plans [Member]                                                                                                                                                                                       |               |          |   |
| **Defined Benefit Plan Disclosure [Line Items]**                                                                                                                                                                    |               |          |   |
| Noncurrent assets                                                                                                                                                                                                   | [1]           | 0             | 0 |
| Current liabilities                                                                                                                                                                                                 | [2]           | (31)          | (27) |
| Noncurrent liabilities                                                                                                                                                                                              | [3]           | (1,809)       | (2,379) |
| Funded status                                                                                                                                                                                                       |               | $ (1,841)     | $ (2,406) |
|                                                                                                                                                                                                                     |
| [1]Included primarily in Other noncurrent assets.[2]Included in Accrued compensation and related items.[3]Included in Pension benefit obligations, net and Postretirement benefit obligations, net, as appropriate. |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate net amount recognized in the balance sheet associated with the defined benefit plan(s). Will normally be the same as the Defined Benefit Plan, Funded Status of Plan, Total.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=21915240&loc=d3e1703-114919Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount for overfunded plans recognized in the balance sheet as a noncurrent asset associated with a defined benefit pension plan or other postretirement 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 (c) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=21915240&loc=d3e1703-114919
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| X                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
For a classified balance sheet, the amount recognized in balance sheet as a current liability associated with an underfunded defined benefit plan.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans.
+ References
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| X                                                                                                                                                                                                                    |
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| X                                                                                                                                                                                                                    |
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| X                                                                                                                                                                                                     |
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| X                                                                                                                                                                                                                 |
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