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Goodwill and Acquired Client Relationships - Schedule of Changes in Goodwill (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014
Changes in goodwill |  |
Balance at the beginning of the period | $ 2,652.8 | $ 2,341.7
Goodwill acquired | 64.3 | 344.5
Foreign currency translation | (48.7) | (33.4)
Balance at the end of the period | 2,668.4 | 2,652.8
Institutional |  |
Changes in goodwill |  |
Balance at the beginning of the period | 1,159.1 | 1,076.3
Goodwill acquired | 9.2 | 97.2
Foreign currency translation | (27.0) | (14.4)
Balance at the end of the period | 1,141.3 | 1,159.1
Mutual Fund |  |
Changes in goodwill |  |
Balance at the beginning of the period | 1,125.3 | 928.1
Goodwill acquired | 0.0 | 208.1
Foreign currency translation | (5.8) | (10.9)
Balance at the end of the period | 1,119.5 | 1,125.3
High Net Worth |  |
Changes in goodwill |  |
Balance at the beginning of the period | 368.4 | 337.3
Goodwill acquired | 55.1 | 39.2
Foreign currency translation | (15.9) | (8.1)
Balance at the end of the period | $ 407.6 | $ 368.4

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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 -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 + Details
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + 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 + Details
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- Definition Amount of increase (decrease) from foreign currency translation adjustments 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 (f) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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