Assets and Liabilities Measured at Fair Value - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	$ 570	$ 628
Less amounts classified as current assets	(55)	(80)
Investments of insurance subsidiaries, noncurrent	515	548
Cross currency swap (Income taxes and other liabilities) [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Liabilities, Fair Value	13
Interest rate swaps [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Liabilities, Fair Value	429	399
Cross currency swap [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Liabilities, Fair Value		16
Auction rate securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	68
Equity securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	3	7
Debt securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	567	621
Debt securities [Member] \| States and municipalities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	418	417
Debt securities [Member] \| Auction rate securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	68	131
Debt securities [Member] \| Asset-backed securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	14	20
Debt securities [Member] \| Money market funds [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	67	53
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	68	54
Less amounts classified as current assets	(55)	(54)
Investments of insurance subsidiaries, noncurrent	13
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) [Member] \| Equity securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	1	1
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) [Member] \| Debt securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	67	53
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) [Member] \| Debt securities [Member] \| Money market funds [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	67	53
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	432	442
Less amounts classified as current assets		(26)
Investments of insurance subsidiaries, noncurrent	432	416
Significant Other Observable Inputs (Level 2) [Member] \| Cross currency swap (Income taxes and other liabilities) [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Liabilities, Fair Value	13
Significant Other Observable Inputs (Level 2) [Member] \| Interest rate swaps [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Liabilities, Fair Value	429	399
Significant Other Observable Inputs (Level 2) [Member] \| Cross currency swap [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Liabilities, Fair Value		16
Significant Other Observable Inputs (Level 2) [Member] \| Equity securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value		5
Significant Other Observable Inputs (Level 2) [Member] \| Debt securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	432	437
Significant Other Observable Inputs (Level 2) [Member] \| Debt securities [Member] \| States and municipalities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	418	417
Significant Other Observable Inputs (Level 2) [Member] \| Debt securities [Member] \| Asset-backed securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	14	20
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	70	132
Investments of insurance subsidiaries, noncurrent	70	132
Significant Unobservable Inputs (Level 3) [Member] \| Equity securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	2	1
Significant Unobservable Inputs (Level 3) [Member] \| Debt securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	68	131
Significant Unobservable Inputs (Level 3) [Member] \| Debt securities [Member] \| Auction rate securities [Member]
Fair Value Assets Measured On Recurring Basis [Line Items]
Assets, Fair Value	$ 68	$ 131

Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Section A

-Paragraph 4, 5

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

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

- Definition

Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

+ References

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

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

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