CONSOLIDATION (Variable Interest Entities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets of consolidated VIEs	$ 13,719,957		$ 13,719,957		$ 12,014,196
Liabilities of consolidated VIEs	11,716,209		11,716,209		10,155,598
Investments in CLO warehouse
Variable Interest Entity [Line Items]
Maximum exposure to loss attributable to the Company's investment in VIEs	79,500		79,500		104,700
Consolidated Funds
Variable Interest Entity [Line Items]
Net income attributable to non-controlling interests	85,186	$ 8,346	(81,220)	$ 25,970
Non-Consolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Maximum exposure to loss attributable to the Company's investment in VIEs	252,564		252,564		260,520
Consolidated VIEs
Variable Interest Entity [Line Items]
Maximum exposure to loss attributable to the Company's investment in VIEs	151,144		151,144		181,856
Consolidated VIEs | Consolidated Funds
Variable Interest Entity [Line Items]
Assets of consolidated VIEs	10,575,113		10,575,113		9,454,572
Liabilities of consolidated VIEs	$ 9,960,904		$ 9,960,904		$ 8,679,869