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Investments in Affiliates and Affiliate Sponsored Investment Products - Affiliate Accounted For Under Equity Method (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Equity method investments in Affiliates (net)	$ 2,791.0	$ 3,304.7
Carrying amount and maximum exposure to loss of equity method affiliates	513.2	539.0
Affiliates accounted for under the equity method
Variable Interest Entity [Line Items]
Unconsolidated VIE Net Assets	1,102.9	1,594.4
Carrying Value and Maximum Exposure to Loss	$ 2,277.8	$ 2,765.7

X

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

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Amount of investment in equity method investee and investment in and advance to affiliate.

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- Definition

Difference between the carrying amount of assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the variable interest entity (VIE) and the reporting entity's maximum exposure to loss as a result of its involvement with the VIE, where the reporting entity is not the VIE's primary beneficiary.

+ References

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Net carrying amount of the assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), when the reporting entity is not the VIE's primary beneficiary.

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