Fair Value Assumptions, Average Projected Growth Rate

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Fair Value Assumptions, Average Projected Growth Rate Period

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Fair Value Assumptions, Discount Rate For Assets Based Fees

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Fair Value Assumptions, Discount Rate For Performance Fees

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Fair Value Assumptions, Market Participant Tax Rate

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Noncontrolling Interest, Notification of Possible Sale of Noncontrolling Interest, Percentage

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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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.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth 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.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth 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.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third 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.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second 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.

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Amount of cash outflow to a noncontrolling interest. Includes, but not limited to, reduction of noncontrolling interest ownership. Excludes dividends paid to the noncontrolling interest.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Equity Method Investments in Affiliates - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Schedule of Equity Method Investments [Line Items]
Amortization expense during the period	$ 21.2		$ 23.2	$ 50.9	$ 46.4
Estimated Future Amortization Expense of Finite-Lived Intangibles
Impairment recognized on equity method investment		$ 415.0
Fair value assumptions, period of projected annual based fee margin growth rate		5 years
Fair value assumptions, projected annual based fee margin growth rate		(13.00%)
Fair value assumptions, discount rate for asset based fees		11.00%
Fair value assumptions, discount rate for performance based fees		20.00%
Fair value assumptions, market participant tax rate		25.00%
Acquired Client Relationships
Schedule of Equity Method Investments [Line Items]
Amortization expense during the period				50.9
Estimated Future Amortization Expense of Finite-Lived Intangibles
Finite-lived intangible, future amortization expense in 2019	100.0			100.0
Finite-lived intangible, future amortization expense in 2020	75.0			75.0
Finite-lived intangible, future amortization expense in 2021	50.0			50.0
Finite-lived intangible, future amortization expense in 2022	50.0			50.0
Finite-lived intangible, future amortization expense in 2023	50.0			50.0
Equity Method Investee \| Acquired Client Relationships
Schedule of Equity Method Investments [Line Items]
Amortization expense during the period	38.9		$ 23.5	62.1	$ 53.5
Estimated Future Amortization Expense of Finite-Lived Intangibles
Finite-lived intangible, future amortization expense in 2019	150.0			150.0
Finite-lived intangible, future amortization expense in 2020	150.0			150.0
Finite-lived intangible, future amortization expense in 2021	75.0			75.0
Finite-lived intangible, future amortization expense in 2022	75.0			75.0
Finite-lived intangible, future amortization expense in 2023	75.0			$ 75.0
Non-US \| Equity Method Investee
Estimated Future Amortization Expense of Finite-Lived Intangibles
Noncontrolling interest, sell of ownership percentage		5.00%
Payments to noncontrolling interest for additional equity interest in affiliate	$ 25.7