| **Summary of Significant Accounting Policies - Narrative (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended |        |
|---------------------------------------------------------------------------------------------------------------------|----------------|--------|
||
| **Accounting Policies [Line Items]**                                                                                |           |   |
| Goodwill                                                                                                            | $ 170          | $ 184  |
| Number Of Segments                                                                                                  | 4              |   |
| Unionized Employees Concentration Risk [Member] | Number Of Employees Hourly Workers [Member]                       |           |   |
| **Accounting Policies [Line Items]**                                                                                |           |   |
| Concentration Risk Number Of Employees                                                                              | 5,700          |   |
| concentration risk number of employees percentage                                                                   | 64.00%         |   |
| Unionized Employees Concentration Risk [Member] | Number of Employees Salaried Workers [Member]                     |           |   |
| **Accounting Policies [Line Items]**                                                                                |           |   |
| Concentration Risk Number Of Employees                                                                              | 400            |   |
| concentration risk number of employees percentage                                                                   | 6.00%          |   |
| Brazilian Reporting Unit [Domain]                                                                                   |           |   |
| **Accounting Policies [Line Items]**                                                                                |           |   |
| Goodwill                                                                                                            | $ 132          |   |

| X                                                                                                                                                       |
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| X                                                                                                                                                                                                                                                        |
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| - Definition
Concentration Risk Number Of Employees
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                           |
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| - Definition
concentration risk number of employees percentage
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.
+ References
No definition available.
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