Retirement and Postretirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined benefit pension plans
Postretirement and Other Benefit Plans Disclosure
Employer contributions		$ 2.0	$ 5.0	$ 3.0
Pension Benefit
Net periodic benefit costs:
Service cost	$ 2.0	3.0	4.0	6.0
Interest cost	5.0	6.0	10.0	12.0
Expected return on plan assets	(7.0)	(9.0)	(14.0)	(17.0)
Recognized actuarial loss	2.0	2.0	4.0	3.0
Net periodic benefit cost	2.0	2.0	4.0	4.0
Postretirement Benefit
Net periodic benefit costs:
Service cost	7.0	6.0	14.0	12.0
Interest cost	10.0	12.0	20.0	24.0
Recognized actuarial loss	7.0	6.0	14.0	12.0
Net periodic benefit cost	$ 24.0	$ 24.0	$ 48.0	$ 48.0

The amount of gains or losses recognized in net periodic benefit cost.

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- Definition

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

+ References

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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.

+ References

No definition available.

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- Definition

An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Expected Return on Plan Assets

-URI http://asc.fasb.org/extlink&oid=6512136

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 60

-Glossary Expected Return on Plan Assets

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- Definition

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.

+ References

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

-Publisher FASB

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-SubTopic 20

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- Definition

The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

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- References

No definition available.

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- Definition

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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Service Cost (Component of Net Periodic Pension Cost)

-URI http://asc.fasb.org/extlink&oid=6525008

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

-Publisher FASB

-Name Accounting Standards Codification

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