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Related Party Transactions (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Related Party Transactions |  |  |
Imputed interest (gains) expenses of contingent payment arrangements | $ (15,500,000) | $ (3,900,000) | $ 40,300,000
Prior Owner | Non- controlling Interests |  |  |
Related Party Transactions |  |  |
Investment partnerships with prior owners |  | 2,500,000 |
Prior Owner | Other Liabilities |  |  |
Related Party Transactions |  |  |
Investment partnerships with prior owners | 61,200,000 | 67,800,000 |
Affiliated Entity |  |  |
Related Party Transactions |  |  |
Imputed interest (gains) expenses of contingent payment arrangements | 6,600,000 | (2,800,000) |
Affiliated Entity | Other Liabilities |  |  |
Related Party Transactions |  |  |
Contingent liabilities arrangements to related parties | 9,400,000 | 8,600,000 |
Payments associated with contingent liabilities arrangements to related parties | $ 6,800,000 | $ 0 |

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- Definition Amount of liability recognized arising from contingent consideration in a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 35 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6911338&loc=d3e6819-128478 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476 + Details
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- Definition Amount of cash outflow, not made soon after acquisition date of business combination, to settle contingent consideration liability exceeding amount recognized at acquisition date. Includes, but is not limited to, measurement period adjustment and less amount paid soon after acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 17 -Subparagraph (ee) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3367-108585 + Details
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