Retirement Benefits - Information Comparing Plan Assets to Plan Obligations (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
US Plans [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets [Abstract]
Fair value of plan assets	$ 786.3	$ 811.8
Accumulated benefit obligation	904.1	934.9
Projected benefit obligation	904.1	934.9
Non-US Plans [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets [Abstract]
Fair value of plan assets	45.6	38.1
Accumulated benefit obligation	111.9	103.6
Projected benefit obligation	137.0	135.1
Pension plan [Member]
Pension plans with an accumulated benefit obligation in excess of plan assets [Abstract]
Fair value of plan assets	831.9	849.9
Accumulated benefit obligation	1,016.0	1,038.5
Projected benefit obligation	$ 1,041.1	$ 1,070.0

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If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 55

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=34716465&loc=d3e4179-114921

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate projected benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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