Fair Value of Financial Instruments (Details) (USD $)	9 Months Ended
Sep. 30, 2011
Debt Instrument [Line Items]
Maturity Date	Jan. 15, 2034
Senior Notes due 2019
Debt Instrument [Line Items]
Face Value of Debt Instrument	$ 500,000,000
Maturity Date	Sep. 15, 2019
Fair Value of Debt Instrument	605,000,000
Senior Notes due 2013
Debt Instrument [Line Items]
Face Value of Debt Instrument	500,000,000
Maturity Date	Aug. 15, 2013
Fair Value of Debt Instrument	549,000,000
Interest Rate Swap
Debt Instrument [Line Items]
Underlying risk	interest rate risk
Notional amount	500,000,000
Type of instrument	interest rate swaps
Hedge designation	fair value hedges
Amount of hedged item	500,000,000
Description of hedged item	$500 million senior notes due 2013
Basis spread on Variable rate	4.377%
Forward Contracts
Debt Instrument [Line Items]
Underlying risk	foreign currency remeasurement gains and losses
Type of instrument	foreign currency forward contracts
Description of hedged item	intercompany notes structured as non-permanent advances
Fair Value Inputs - Level 2
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest Rate Fair Value Hedge Asset	14,840,000
Forward Currency Contract Fair Value Asset	$ 3,400,000

Total monetary amount specified by the derivative(s). Expressed as an absolute value.

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated fair value of the debt instrument at the balance-sheet date.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

+ Details

Name:	us-gaap_DebtInstrumentFairValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, which may be presented in a variety of ways (year, month and year, day, month and year, quarter, etc.).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the hedged item as of the balance sheet date related to the derivative. For example, the hedged balance on a debt instrument.

+ Details

Name:	us-gaap_DerivativeAmountOfHedgedItem
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The average percentage points added to the reference rate to compute the variable rate on the group of interest rate derivatives.

+ Details

Name:	us-gaap_DerivativeAverageBasisSpreadOnVariableRate
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the hedged item related to the derivative. Includes the type of instrument hedged, contract amount, term, and so forth.

+ Details

Name:	us-gaap_DerivativeDescriptionOfHedgedItem
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The hedge designation, if any, elected for the derivative.

+ Details

Name:	us-gaap_DerivativeHedgeDesignation
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the type of derivative instrument, such as a swap, forward, and option. Excludes the underlying risk of the instrument.

+ Details

Name:	us-gaap_DerivativeTypeOfInstrument
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the primary underlying risk exposure associated with the derivative. For example, interest rate risk, credit risk, foreign exchange rate risk, or overall price risk.

+ Details

Name:	us-gaap_DerivativeUnderlyingRisk
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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.

+ Details

Name:	us-gaap_FairValueAssetsMeasuredOnRecurringBasisFinancialStatementCaptionsLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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 contracts related to the exchange of different currencies, including foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into and existing as of the balance sheet date.

+ Details

Name:	us-gaap_ForeignCurrencyContractAssetFairValueDisclosure
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of all derivative assets designated as interest rate fair value hedging instruments.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 17

+ Details

Name:	us-gaap_InterestRateFairValueHedgeAssetAtFairValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant