COMMITMENTS AND CONTINGENCIES (Leases: Assets and Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating lease liabilities	$ 161,737
Finance lease obligations	1,306
Accumulated amortization	$ 900	$ 600
Finance lease assets, extensible list	us-gaap:OtherAssets
Finance lease, liability, extensible list	us-gaap:AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent
Ares Management L.P
Lessee, Lease, Description [Line Items]
Operating lease assets	$ 136,392	143,406
Finance lease assets	1,508	1,787
Total lease assets	137,900	145,193
Operating lease liabilities	161,737	168,817
Finance lease obligations	1,306	1,651
Total lease liabilities	$ 163,043	$ 170,468
Minimum
Lessee, Lease, Description [Line Items]
Lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lease term	10 years