Employee Benefit Plans (Details 8) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
The "DC" Plan
Defined Contribution Retirement Plans
Maximum voluntary contribution by eligible U.S. employees as a percentage of their compensation	50.00%
Number of shares contributed	167	206	266
Compensation expense	$ 16.4	$ 15.3	$ 15.5
Supplemental Retirement Savings Plan (SRSP)
Defined Contribution Retirement Plans
Compensation expense	0.6	0.3	0.3
Supplemental Retirement Savings Plan (SRSP) \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Contribution Retirement Plans
Fair value of plan assets	$ 50.5	$ 46.2

Represents the number of shares contributed by the entity under the defined contribution plan.

No definition available.

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- Definition

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.

+ 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 (b)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Section 35

-Paragraph 50

-URI http://asc.fasb.org/extlink&oid=29635418&loc=d3e12355-114930

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

+ Details

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Balance Type:	debit
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- Details

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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- Details

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- Details

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