Employee benefit Plans - Individually Significant Multiemployer Pension Plans (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Multiemployer Plans [Line Items]
Company Contributions	$ 32	$ 29	$ 29
Total contributions to other multi employer pension plans	7	7	7
Total contributions to multi employer pension plans	39	36	36
Automotive Industries Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	941133245
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	Various dates through 08/31/2014
Company Contributions	1	1	1
Central States, Southeast and Southwest Areas Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	366044243
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Distributors Association Warehousemens Pension Trust [Member]
Multiemployer Plans [Line Items]
EIN	940294755
Pension Plan Number	002
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	5/31/2010; negotiations ongoing
Company Contributions	1	1	1
Local 731 Private Scavengers and Garage Attendants Pension Trust Fund [Member]
Multiemployer Plans [Line Items]
EIN	366513567
Pension Plan Number	001
Pension Protection Act Zone Status	Yellow	Yellow
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	09/30/2013 and 09/30/2014
Company Contributions	5	4	4
New England Teamsters and Trucking Industry Pension Fund [Member]
Multiemployer Plans [Line Items]
EIN	046372430
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	02/28/2013
Suburban Teamsters of Northern Illinois Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	366155778
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	Various dates through 03/31/2015
Company Contributions	2	2	2
Teamsters Employers Local 945 Pension Fund [Member]
Multiemployer Plans [Line Items]
EIN	226196388
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	Various dates through 12/31/2015
Western Conference of Teamsters Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	916145047
Pension Plan Number	001
Pension Protection Act Zone Status	Green	Green
FIP/RP Status	NA
Expiration date of Collective-Bargaining Agreement	Various dates through 05/31/2018
Company Contributions	22	20	20
Western Pennsylvania Teamsters and Employers Pension Plan [Member]
Multiemployer Plans [Line Items]
EIN	256029946
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP/RP Status	Implemented
Expiration date of Collective-Bargaining Agreement	12/31/2016
Company Contributions	$ 1	$ 1	$ 1

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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

-Publisher SEC

-Name Regulation 12B

-Number 240

-Section 12b

-Subsection 1

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- Definition

Three digit plan number for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 5

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450657-114947

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- Definition

Amount of contributions made to multiemployer plans by the employer. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450702-114947

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450691-114947

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 80

-Section 50

-Paragraph 5

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- Definition

Indicate the multiemployer plan's certified zone status as currently required by the Pension Protection Act of 2006 or a subsequent amendment thereof. The zone status categories are red (critical status), orange (seriously endangered), yellow (endangered), and green (none of the above). The acceptable values are "red", "orange", "yellow", "green", "other", and "NA". A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 5

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450657-114947

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- Definition

Description of the significant collective-bargaining arrangements within the range of expiration dates for collective-bargaining arrangements requiring contributions to a multiemployer plan as well as other information to help investors understand the significance of the collective-bargaining agreements and when they expire. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 5

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450657-114947

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- Definition

Indicate whether a funding improvement plan or rehabilitation plan has been implemented or is pending for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "pending", "implemented", "other", and "NA".

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 5

-Subparagraph (f)(1)

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450657-114947

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Amount of contributions made to the multiemployer plan by all employers who participate in the plan. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 80

-Section 50

-Paragraph 7

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450678-114947

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- Definition

Contributions To Other Multiemployer Plans

+ References

No definition available.

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