Stock-Based Compensation (Details 10) (Stock Appreciation Rights [Member], USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Stock Appreciation Rights [Member]
Summary of stock appreciation rights outstanding
Range of Exercise Prices per Share, lower range limit	$ 28.24
Range of Exercise Prices per Share, upper range limit	$ 51.40
Stock Appreciation Rights Outstanding, Weighted-Average Remaining Contractual Term (in years)	4 years 9 months 24 days
Stock Appreciation Rights Outstanding, Aggregate Instrinsic Value	$ 30.0
Stock Appreciation Rights Exercisable, Weighted-Average Remaining Contractual Term (in years)	3 years 8 months 24 days
Stock Appreciation Rights Exercisable, Aggregate Intrinsic Value	$ 21.3

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of options outstanding.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

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-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 2

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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