EQUITY BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended		9 Months Ended
	Nov. 02, 2017	Nov. 30, 2016	Feb. 29, 2016	Sep. 30, 2020	Sep. 30, 2019
KKR Group Partnership | KKR Holdings
Equity Based Payments
Percentage owned by KKR Holdings L.P.				33.00%	35.10%
KKR Holdings Principal Awards
Equity Based Payments
Vesting period (in years)		5 years
Minimum transfer restriction period with respect to one-half awards vested (in years)				1 year
Portion of awards vested having one-year transfer restriction period (as a percent)				50.00%
Minimum transfer restriction period with respect to remaining one-half awards vested (in years)				2 years
Portion of awards vested having two-year transfer restriction period (as a percent)				50.00%
Minimum retained ownership required to continuously hold common share equivalents to as percentage of cumulatively vested interests				25.00%
Forfeiture rate assumed (as a percent)				7.00%
Estimated unrecognized equity-based payment expense		$ 320.9		$ 87.1
Weighted average remaining vesting period over which unvested units are expected to vest (in years)				1 year
Common units conversion basis				1
Number of common units owned in KKR Group Partnership Units (in shares)				278,781,478	295,746,147
Percentage of outstanding units not granted (less than)				1.20%
Modified awards granted (in shares)			28,900,000
KKR Holdings Principal Awards | Minimum
Equity Based Payments
Vesting period (in years)				3 years
KKR Holdings Principal Awards | Maximum
Equity Based Payments
Vesting period (in years)				5 years
Equity Incentive Plans
Equity Based Payments
Total awards issuable as a percentage of diluted common stock outstanding				15.00%
Minimum retained ownership required to continuously hold common share equivalents to as percentage of cumulatively vested interests				15.00%
Forfeiture rate assumed (as a percent)				7.00%
Estimated unrecognized equity-based payment expense				$ 168.8
Weighted average remaining vesting period over which unvested units are expected to vest (in years)				10 months 24 days
Equity Incentive Plans | Minimum
Equity Based Payments
Vesting period (in years)				3 years
Equity Incentive Plans | Maximum
Equity Based Payments
Vesting period (in years)				5 years
Equity Incentive Plans | Market Condition Awards
Equity Based Payments
Awards granted per individual (in shares)	2,500,000
Performance condition, closing market price (in dollars per share)	$ 40
Required term of performance condition (in days)	10 days
Fair value of award at grant date (in dollars per share)	$ 4.02
Compensation expense recognition period (in years)				3 years
Estimated unrecognized equity-based payment expense				$ 0.6
Equity Incentive Plans | KKR Holdings
Equity Based Payments
Minimum transfer restriction period with respect to one-half awards vested (in years)				1 year
Portion of awards vested having one-year transfer restriction period (as a percent)				50.00%
Minimum transfer restriction period with respect to remaining one-half awards vested (in years)				2 years
Portion of awards vested having two-year transfer restriction period (as a percent)				50.00%