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Goodwill and Acquired Client Relationships (Tables) | 12 Months Ended
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Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract] |
Schedule of Changes in Goodwill | The following tables present the changes in the Company’s consolidated Affiliates’ Goodwill and components of Acquired client relationships (net):
|  | Goodwill
|  | 2019 |  | 2020
Balance, beginning of period |  | $ | 2,633.4 |  |  | $ | 2,651.7 |
Foreign currency translation |  | 18.3 |  |  | 11.6 |
Other |  | — |  |  | (1.9) |
Balance, end of period |  | $ | 2,651.7 |  |  | $ | 2,661.4 |
Schedule of Changes in, and the Components of, Acquired Client Relationships |
|  | Acquired Client Relationships (Net)
|  | Definite-lived |  | Indefinite-lived |  | Total
|  | Gross Book Value |  | Accumulated Amortization |  | Net Book Value |  | Net Book Value |  | Net Book Value
Balance, as of December 31, 2018 |  | $ | 1,279.8 |  |  | $ | (976.2) |  |  | $ | 303.6 |  |  | $ | 1,006.3 |  |  | $ | 1,309.9 |
Intangible amortization and impairments |  | — |  |  | (93.4) |  |  | (93.4) |  |  | (51.1) |  |  | (144.5) |
Foreign currency translation |  | 5.1 |  |  | (5.5) |  |  | (0.4) |  |  | 17.0 |  |  | 16.6 |
Transfers(1) |  | (36.1) |  |  | 36.1 |  |  | — |  |  | — |  |  | — |
Balance, as of December 31, 2019 |  | $ | 1,248.8 |  |  | $ | (1,039.0) |  |  | $ | 209.8 |  |  | $ | 972.2 |  |  | $ | 1,182.0 |
Intangible amortization and impairments |  | — |  |  | (69.8) |  |  | (69.8) |  |  | (70.7) |  |  | (140.5) |
Foreign currency translation |  | 3.5 |  |  | (3.7) |  |  | (0.2) |  |  | 7.5 |  |  | 7.3 |
Transfers(1) |  | (85.7) |  |  | 85.7 |  |  | — |  |  | — |  |  | — |
Balance, as of December 31, 2020 |  | $ | 1,166.6 |  |  | $ | (1,026.8) |  |  | $ | 139.8 |  |  | $ | 909.0 |  |  | $ | 1,048.8 |
__________________________ (1)Transfers include acquired client relationships at Affiliates that were deconsolidated during the period.

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- Definition Tabular disclosure of intangibles assets, in total and by major class, including the gross carrying amount and accumulated amortization. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. + References No definition available. + Details
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- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267 + Details
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