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Payments To Acquire Seed Investments

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Ratio of Third-Party Borrowings to Trailing Twelve Months Adjusted EBITDA

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount, after accumulated amortization, of debt discount.

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Weighted average interest rate of debt outstanding.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Aggregate amount of interest paid or due on all long-term debt.

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The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Borrowings and Debt - Narrative (Details) - USD ($)			1 Months Ended	3 Months Ended	12 Months Ended
Borrowings and Debt - Narrative (Details) - USD ($)	Aug. 20, 2019	Jul. 17, 2017	Jul. 31, 2016	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 19, 2019	Jul. 31, 2017
Borrowings and debt
Long term debt					$ 568,800,000	$ 393,300,000
Interest expense					$ 32,200,000	$ 24,900,000	$ 24,500,000
Consolidated Entity Excluding Consolidated Funds
Borrowings and debt
Weighted average interest rate					5.28%	6.08%	6.02%
Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility \| Minimum
Borrowings and debt
Undrawn amounts fee (as a percent)	0.125%
Interest coverage ratio					4.0
Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility \| Maximum
Borrowings and debt
Undrawn amounts fee (as a percent)	0.45%
Ratio of third-party borrowings to trailing twelve months Adjusted EBITDA					3.0
Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility \| Federal Funds Effective Swap Rate
Borrowings and debt
Variable rate margin (as a percent)	0.50%
Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility \| One Month Adjusted London Interbank Offered Rate LIBOR
Borrowings and debt
Variable rate margin (as a percent)	1.00%
Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility \| One, two, three or six months rate LIBOR \| Minimum
Borrowings and debt
Variable rate margin (as a percent)	1.125%
Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility \| One, two, three or six months rate LIBOR \| Maximum
Borrowings and debt
Variable rate margin (as a percent)	2.00%
Credit Facility \| Revolving credit facility \| LIBOR
Borrowings and debt
Variable rate margin (as a percent)					1.50%
Undrawn amounts fee (as a percent)					0.20%
Non-recourse Seed Capital Facility \| Credit Facility
Borrowings and debt
Maximum borrowing capacity		$ 65,000,000.0
Undrawn amounts fee (as a percent)		0.95%
Long term debt					$ 35,000,000.0
Maximum borrowing capacity as percent of seed capital		50.00%
Non-recourse Seed Capital Facility \| Credit Facility \| LIBOR
Borrowings and debt
Variable rate margin (as a percent)		1.55%
Senior Notes, 4.80%, due 2026 \| Senior notes
Borrowings and debt
Maturity amount			$ 275,000,000.0		$ 275,000,000
Interest rate (as a percent)			4.80%		4.80%
Debt instrument, unamortized discount			$ 500,000
Debt issuance costs			$ (3,000,000.0)
Term of loan			10 years
Debt instrument, redemption price, percentage			100.00%
Debt instrument, redemption price, percentage of accrued or unpaid interest			0.50%
Senior Notes, 5.125%, due 2031 \| Senior notes
Borrowings and debt
Maturity amount			$ 125,000,000.0		$ 125,000,000
Interest rate (as a percent)			5.125%		5.125%
Debt issuance costs			$ (4,300,000)
Term of loan			15 years
Debt instrument, redemption price, percentage			100.00%
Parent Company
Borrowings and debt
Payments to acquire seed investments									$ 63,400,000
Citibank \| Line of Credit \| Revolving credit facility
Borrowings and debt
Maturity amount	$ 450,000,000							$ 350,000,000
Line of Credit Facility, Additional Borrowing Amount	150,000,000
Proceeds from Lines of Credit	210,000,000
Repayments of Lines of Credit	210,000,000			$ 70,000,000
Citibank \| Line of Credit \| Consolidated Entity Excluding Consolidated Funds \| Revolving credit facility
Borrowings and debt
Maximum borrowing capacity	$ 450,000,000