SEGMENT REPORTING - Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets	$ 50,343,948	$ 45,834,719	$ 44,305,639
Deduct: Carry Pool Reclassification from Liabilities	1,300,165	1,220,559
Deduct: Impact of KKR Management Holdings Corp.	2,247,747	$ 2,531,075
Segment Reconciling Items
Segment Reporting, Asset Reconciling Item [Line Items]
Deduct: Impact of Consolidation of Funds and Other Entities	30,354,674		27,524,641
Deduct: Carry Pool Reclassification from Liabilities	1,300,165		1,131,071
Add: Tax Reclassifications	83,766		0
Deduct: Impact of KKR Management Holdings Corp.	0		301,928
Reportable segments
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets	$ 18,772,875		$ 15,347,999