Retirement Benefits - Information Comparing Plan Assets to Plan Obligations (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
U.S. Plans
Information for pension plans with an ABO in excess of plan assets:
Fair value of plan assets	$ 728.5	$ 721.4
Accumulated benefit obligation	845.9	844.8
Projected benefit obligation	845.9	844.8
Non-U.S. Plans
Information for pension plans with an ABO in excess of plan assets:
Fair value of plan assets	41.3	47.7
Accumulated benefit obligation	107.3	111.9
Projected benefit obligation	127.9	135.2
Total
Information for pension plans with an ABO in excess of plan assets:
Fair value of plan assets	769.8	769.1
Accumulated benefit obligation	953.2	956.7
Projected benefit obligation	$ 973.8	$ 980.0

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- Definition

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=73719040&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=65897934&loc=d3e2417-114920

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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

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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

Reference 1: 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=65897934&loc=d3e2417-114920

Reference 2: 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=73719040&loc=d3e4179-114921

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