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Goodwill and Acquired Client Relationships - Schedule of Changes in Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	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

X

- 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

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-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

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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
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+ References

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-Topic 350
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