DEBT OBLIGATIONS AND CREDIT FACILITIES - Debt Obligations (Details) - USD ($)	6 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Less: Debt issuance costs	$ (4,818,000)	$ (5,569,000)
Debt obligations	909,681,000	864,529,000
Oaktree Capital Group Excluding Consolidated Funds
Debt Instrument [Line Items]
Total remaining principal	750,000,000	750,000,000
Less: Debt issuance costs	(3,790,000)	(4,055,000)
Debt obligations	746,210,000	745,945,000
Oaktree Capital Group Excluding Consolidated Funds \| Senior secured notes \| $250,000, 3.78%, issued in December 2017, payable on December 18, 2032
Debt Instrument [Line Items]
Total remaining principal	250,000,000	250,000,000
Face amount	$ 250,000,000
Stated percentage	3.78%
Oaktree Capital Group Excluding Consolidated Funds \| Senior secured notes \| $50,000, 3.91%, issued in September 2014, payable on September 3, 2024
Debt Instrument [Line Items]
Total remaining principal	$ 50,000,000	50,000,000
Face amount	$ 50,000,000
Stated percentage	3.91%
Oaktree Capital Group Excluding Consolidated Funds \| Senior secured notes \| $100,000, 4.01%, issued in September 2014, payable on September 3, 2026
Debt Instrument [Line Items]
Total remaining principal	$ 100,000,000	100,000,000
Face amount	$ 100,000,000
Stated percentage	4.01%
Oaktree Capital Group Excluding Consolidated Funds \| Senior secured notes \| $100,000, 4.21%, issued in September 2014, payable on September 3, 2029
Debt Instrument [Line Items]
Total remaining principal	$ 100,000,000	100,000,000
Face amount	$ 100,000,000
Stated percentage	4.21%
Oaktree Capital Group Excluding Consolidated Funds \| Senior secured notes \| $100,000, 3.69%, issued in July 2016, payable on July 12, 2031
Debt Instrument [Line Items]
Total remaining principal	$ 100,000,000	100,000,000
Face amount	$ 100,000,000
Stated percentage	3.69%
Oaktree Capital Group Excluding Consolidated Funds \| Credit Agreement \| $250,000, variable-rate term loan, issued in March 2014, payable on March 29, 2023
Debt Instrument [Line Items]
Total remaining principal	$ 150,000,000	$ 150,000,000
Face amount	$ 250,000,000
Unused commitment fee	1.00%
Oaktree Capital Group Excluding Consolidated Funds \| Credit Agreement \| Revolving credit facility
Debt Instrument [Line Items]
Credit facility	$ 500,000,000
Unused commitment fee	0.10%
Borrowings under credit facilities	$ 0

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
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-Subparagraph (b)(1)
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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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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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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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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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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit 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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