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Retirement Benefits (Details 12) - Pension Benefits [Member] - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | $ 1,962.3 | $ 2,204.4
Net Realized and Unrealized Gains (Losses) | 79.7 | (41.1)
Fair value of plan assets at end of year | 1,894.6 | 1,962.3
Fixed income and cash equivalents [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 369.7 |
Fair value of plan assets at end of year | 412.2 | 369.7
Floating rate [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 358.0 |
Fair value of plan assets at end of year | 164.0 | 358.0
Private equity [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 201.2 |
Fair value of plan assets at end of year | 204.1 | 201.2
Hedge funds [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 51.9 |
Fair value of plan assets at end of year | 283.9 | 51.9
Real estate and other [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 186.5 |
Fair value of plan assets at end of year | 96.5 | 186.5
Significant Unobservable Inputs (Level 3) [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 305.6 | 361.3
Net Realized and Unrealized Gains (Losses) | 12.1 | 4.4
Net Purchases, Issuances and Settlements | (218.4) | (60.1)
Net Transfers Into (Out Of) Level 3 | 0.0 | 0.0
Fair value of plan assets at end of year | 99.3 | 305.6
Significant Unobservable Inputs (Level 3) [Member] | Fixed income and cash equivalents [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0.3 | 0.3
Net Realized and Unrealized Gains (Losses) | 0.0 | 0.0
Net Purchases, Issuances and Settlements | (0.1) | 0.0
Net Transfers Into (Out Of) Level 3 | 0.0 | 0.0
Fair value of plan assets at end of year | 0.2 | 0.3
Significant Unobservable Inputs (Level 3) [Member] | Floating rate [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 305.3 | 361.0
Net Realized and Unrealized Gains (Losses) | 12.1 | 4.4
Net Purchases, Issuances and Settlements | (218.3) | (60.1)
Net Transfers Into (Out Of) Level 3 | 0.0 | 0.0
Fair value of plan assets at end of year | 99.1 | 305.3
Significant Unobservable Inputs (Level 3) [Member] | Private equity [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0.0 |
Fair value of plan assets at end of year | 0.0 | 0.0
Significant Unobservable Inputs (Level 3) [Member] | Hedge funds [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0.0 |
Fair value of plan assets at end of year | 0.0 | 0.0
Significant Unobservable Inputs (Level 3) [Member] | Real estate and other [Member] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0.0 |
Fair value of plan assets at end of year | $ 0.0 | $ 0.0

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- Definition 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 -Name Accounting Standards Codification -Glossary Actual Return on Plan Assets (Component of Net Periodic Postretirement Benefit Cost) -URI http://asc.fasb.org/extlink&oid=6504192 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Actual Return on Plan Assets (Component of Net Periodic Pension Cost) -URI http://asc.fasb.org/extlink&oid=6504226 + Details
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- Definition Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees. + References Reference 1: 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=64937038&loc=d3e12355-114930 Reference 2: 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=65897934&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Plan Assets -URI http://asc.fasb.org/extlink&oid=6749337 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Plan Assets -URI http://asc.fasb.org/extlink&oid=6520858 + Details
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