v2.4.0.6

Derivative Financial Instruments (Schedule of Foreign Currency Derivative) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2011
Derivative Financial Instruments [Abstract] |
CAD Notional | $ 305
Expiration | March 30, 2012
Fixed Rate Received | 0.9812
Contract Type | Sell

X
- Definition The entity's designation of its position on the foreign currency contract being described. This flag can only have the values of "Buy" or "Sell". + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 + Details
Name: | invest_InvestmentForeignCurrencyContractTransactionTypeFlag
Namespace Prefix: | invest_
Data Type: | invest:foreignCurrencyContractTransactionItemType
Balance Type: | na
Period Type: | duration

X
- Definition The contractual rate at which a foreign currency can be purchased or sold under the terms of a foreign currency derivative contract. + References No definition available. + Details
Name: | us-gaap_DerivativeForwardExchangeRate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when foreign currency exchange rate derivatives mature or expire. + References No definition available. + Details
Name: | us-gaap_MaturityOfForeignCurrencyDerivatives
Namespace Prefix: | us-gaap_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate notional amount of foreign currency exchange rate derivatives. Notional amount refers to the number of currency units specified in the foreign currency derivative contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Notional Amount -URI http://asc.fasb.org/extlink&oid=6519104 + Details
Name: | us-gaap_NotionalAmountOfForeignCurrencyDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant