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Equity Method Investments in Affiliates - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Schedule of Equity Method Investments |  |  |
Amortization period for tax deductible goodwill |  | 15 years |
Amortization expense during the period | $ 110.2 | $ 115.4 | $ 122.2
Undistributed earnings from equity method affiliates | $ 134.3 |  |
Acquired Client Relationships Under Equity Method Investments |  |  |
Schedule of Equity Method Investments |  |  |
Amortization period for tax deductible goodwill | 15 years |  |
Payment of contingent payment liability | $ 23.3 |  |
Weighted average life | 14 years |  |
Amortization expense during the period | $ 59.2 | $ 34.3 |
Annual amortization expense Year 1 | 80.0 |  |
Annual amortization expense Year 2 | 80.0 |  |
Annual amortization expense Year 3 | 80.0 |  |
Annual amortization expense Year 4 | 80.0 |  |
Annual amortization expense Year 5 | $ 80.0 |  |

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- Definition For contingent consideration arrangements recognized in connection with a business combination, this element represents the expected payment amount related to equity method investments during the period. + References No definition available. + Details
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- Definition Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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