Employee Retirement Plans (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Obligations and Funded Status
Accumulated Benefit Obligations	$ 473.8	$ 392.1
Projected Benefit Obligations:
Beginning of year	392.1	442.5
Service cost	0.5us-gaap_DefinedBenefitPlanServiceCost	1.1us-gaap_DefinedBenefitPlanServiceCost	0.9us-gaap_DefinedBenefitPlanServiceCost
Interest	20.2us-gaap_DefinedBenefitPlanInterestCost	18.5us-gaap_DefinedBenefitPlanInterestCost	19.4us-gaap_DefinedBenefitPlanInterestCost
Benefits paid	(16.4)us-gaap_DefinedBenefitPlanBenefitsPaid	(15.8)us-gaap_DefinedBenefitPlanBenefitsPaid
Actuarial (gain)/loss	77.6	(54.2)
Curtailment	(0.1)us-gaap_DefinedBenefitPlanCurtailments	0us-gaap_DefinedBenefitPlanCurtailments
End of year	473.9	392.1	442.5
Plans' Assets:
Beginning of year	399.2	340.1
Actual return on assets	36.7	56.0
Employer contributions	15.0	18.9
Benefits paid	(16.4)us-gaap_DefinedBenefitPlanBenefitsPaid	(15.8)us-gaap_DefinedBenefitPlanBenefitsPaid
End of year	434.5	399.2	340.1
Consolidated Balance Sheet Components:
Net funded status	(39.4)	7.1
Percent of projected benefit obligations funded	91.70%	101.80%
Other assets
Consolidated Balance Sheet Components:
Net funded status	1.2	17.8
Accrued liabilities
Consolidated Balance Sheet Components:
Net funded status	$ (40.4)	$ (10.7)

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

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-Name Accounting Standards Codification

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The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable.

+ References

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

-Publisher FASB

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-Glossary Actual Return on Plan Assets (Component of Net Periodic Postretirement Benefit Cost)

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Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

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1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date.

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The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

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The increase in the fair value of plan assets from contributions made by the employer.

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The amount of decrease that is related to an event that significantly reduces the expected years of future service of present employees or eliminates for a significant number of employees the accrual of defined benefits for some or all of their future services.

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

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Plan assets of a defined benefit plan, as a percentage of projected benefit obligation.

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The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total.

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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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