Represents the entity's future capital commitments related to a limited partner investment.

No definition available.

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-- None. No documentation exists for this element. --

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Cash collateral deposited with a broker for securities sold short

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Line items represent reporting 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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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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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 cost 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. 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 deferred tax liability attributable to taxable temporary differences not separately disclosed.

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The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).

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The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

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Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Investments (Details) - USD ($) $ in Millions	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Investments
Carrying Value	$ 333.6		$ 333.6		$ 418.2
Available-for-sale securities
Book cost basis	29.4		29.4		83.4
Gross unrealized gains	100.0		100.0		136.2
Gross unrealized loss	0.0		0.0		0.1
Market value	129.4		129.4		219.5
Proceeds from sale of investments			59.4	$ 224.5
Gross realized gains	0.0	$ 87.8	5.8	163.3
Gross realized losses	0.0	0.9	3.7	2.4
Other than Temporary impairment
Lower of cost or market valuation adjustments on cost method investments	0.0	$ 0.0	0.0	$ 0.0
Seed capital investments cash collateral	14.3		14.3		10.8
Variable Interest Entity, Maximum Loss Exposure, Amount	113.9		113.9		120.9
Cost method, private equity and other investments
Investments
Carrying Value	16.8		16.8		16.0
Private Equity Funds
Investments
Carrying Value	109.4		109.4		117.2
Future capital commitments
Future capital commitments related to private equity fund investments	4.5		4.5
Available-for-sale securities
Investments
Carrying Value	129.4		129.4		219.5
Deferred Tax Liabilities	41.7		41.7		54.8
Available-for-sale securities \| State Street Corporation
Investments
Carrying Value	117.7		117.7		144.8
Available-for-sale securities \| Other available-for-sale securities
Investments
Carrying Value	11.7		11.7		74.7
Other investments
Investments
Carrying Value	204.2		204.2		198.7
Other investments \| Trading securities
Investments
Carrying Value	13.1		13.1		14.8
Other investments \| Seed Capital Investments
Investments
Carrying Value	64.9		64.9		50.7
Other investments \| Cost method, private equity and other investments
Investments
Carrying Value	$ 126.2		$ 126.2		$ 133.2