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Goodwill and Other Intangible Assets (Goodwill and Intangible Assets Rollforward) (Details) - USD ($) $ in Millions |  | 12 Months Ended
--- | --- | ---
Oct. 05, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Goodwill [Roll Forward] |  |  |  |
Beginning balance |  | $ 25.9 | $ 18.6 |
Acquisitions of businesses and asset groups (2) |  |  | 7.6 |
Wobi write-off |  |  | (0.3) |
Ending balance |  | 25.9 | 25.9 | $ 18.6
Finite-lived Intangible Assets [Roll Forward] |  |  |  |
Beginning balance |  | 19.3 |  |
Amortization, including foreign currency translation |  | (10.7) | (10.5) | (8.4)
Ending balance |  | 36.2 | 19.3 |
Payments to acquire businesses and interest in affiliates |  | 27.6 | 13.4 | 2.6
Other intangible assets |  |  |  |
Finite-lived Intangible Assets [Roll Forward] |  |  |  |
Beginning balance |  | 19.3 | 26.9 |
Acquisitions of businesses and asset groups (2) |  | 27.6 | 5.0 |
Wobi write-off |  |  | (2.5) |
Amortization, including foreign currency translation |  | (10.7) | (10.5) |
Ending balance |  | $ 36.2 | 19.3 | 26.9
Star & Shield LLC | Other intangible assets |  |  |  |
Finite-lived Intangible Assets [Roll Forward] |  |  |  |
Add: Star & Shield amounts held for sale at beginning of the period |  |  | $ 0.4 |
Less: Star & Shield amounts held for sale at end of the period |  |  |  | $ 0.4
Healthplans.com |  |  |  |
Finite-lived Intangible Assets [Roll Forward] |  |  |  |
Payments to acquire businesses and interest in affiliates | $ 28.0 |  |  |

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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=98514028&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=84176398&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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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
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- Definition Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph ((a)(1),(b)) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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