DEBT OBLIGATIONS AND CREDIT FACILITIES - Credit Facilities of Consolidated Funds (Details) - Consolidated VIEs - USD ($)	12 Months Ended
Dec. 31, 2019	Sep. 30, 2020
Debt Instrument [Line Items]
Long-term debt, gross		$ 6,478,508,000
Total debt obligations, net	$ 5,767,999,000	6,241,881,000
Credit Agreement
Debt Instrument [Line Items]
Long-term debt, gross	159,411,000	0
Less: Debt issuance costs	(934,000)	0
Total debt obligations, net	158,477,000	$ 0
Senior variable rate notes key terms as of December 31, 2019	$ 159,411,000
Weighted Average Interest Rate	3.42%
Weighted Average Remaining Maturity (years)	4 years 4 months 24 days

Debt Instrument, Weighted Average Remaining Term

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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- Definition

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.

+ References

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- Definition

Weighted average interest rate of debt outstanding.

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No definition available.

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- Definition

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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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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- Definition

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.

+ References

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