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Goodwill and Other Intangible Assets - Goodwill Rollforward (Details) - USD ($) $ in Millions | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2017 | Mar. 31, 2016 | Dec. 31, 2016 | Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |  |
Goodwill | $ 31.7 | $ 24.1 | $ 31.7 | $ 24.1
Intangible Assets, Net (Excluding Goodwill) | 21.3 | 32.2 | 24.2 | 31.3
Goodwill and other intangible assets | 53.0 | 56.3 | 55.9 | 55.4
Acquisition of businesses | 0.0 | 3.9 |  |
Disposal Group, Including Discontinued Operation, Intangible Assets | 0.0 | 0.3 | 0.0 | 0.4
Amortization of Intangible Assets | (2.9) | (3.1) |  |
Intangible Asset and Goodwill [Member] |  |  |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |  |  |
Acquisition of businesses |  | 3.9 |  |
Disposal Group, Including Discontinued Operation, Intangible Assets | 0.0 | 0.3 | $ 0.0 | $ 0.4
Amortization of Intangible Assets | $ (2.9) | $ (3.1) |  |

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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- Definition Amount classified as intangible assets, excluding goodwill, attributable to disposal group held for sale or disposed of. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=64862545&loc=d3e2941-110230 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=65878427&loc=SL51721533-107759 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=65878427&loc=d3e1107-107759 + Details
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