Pension Benefits - Pension Benefit Payments (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended
Dec. 31, 2012 Pension Plans, Defined Benefit [Member]	Dec. 31, 2011 Supplemental Employee Retirement Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected Future Benefit Payments In 2013	$ 22.7
Expected Future Benefit Payments in 2014	23.9
Expected Future Benefit Payments in 2015	25.0
Expected Future Benefit Payments in 2016	26.2
Expected Future Benefit Payments in 2017	27.4
Expected Future Benefit Payments in 2018-2022	155.3
Actuarial Gain Recognized in Other Comprehensive Income, Before Tax		$ 2.9

Actuarial Gain Recognized in Other Comprehensive Income, Before Tax

No definition available.

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- Definition

Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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- Definition

Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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- Definition

Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.

+ References

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