EQUITY BASED COMPENSATION - Remaining Vesting Tranches (Details) - shares	Sep. 30, 2020	Dec. 31, 2019
Equity Incentive Plans
Equity Based Payments
Principal units (in shares)	15,650,202	22,697,645
Equity Incentive Plans | October 1, 2020
Equity Based Payments
Principal units (in shares)	4,013,270
Equity Incentive Plans | April 1, 2021
Equity Based Payments
Principal units (in shares)	4,639,350
Equity Incentive Plans | October 1, 2021
Equity Based Payments
Principal units (in shares)	2,648,552
Equity Incentive Plans | April 1, 2022
Equity Based Payments
Principal units (in shares)	1,620,660
Equity Incentive Plans | October 1, 2022
Equity Based Payments
Principal units (in shares)	1,402,618
Equity Incentive Plans | April 1, 2023
Equity Based Payments
Principal units (in shares)	837,401
Equity Incentive Plans | October 1, 2023
Equity Based Payments
Principal units (in shares)	168,537
Equity Incentive Plans | April 1, 2024
Equity Based Payments
Principal units (in shares)	187,970
Equity Incentive Plans | October 1, 2024
Equity Based Payments
Principal units (in shares)	5,133
Equity Incentive Plans | April 1, 2025
Equity Based Payments
Principal units (in shares)	126,711
KKR Holdings Principal Awards
Equity Based Payments
Principal units (in shares)	13,180,000	16,569,479
KKR Holdings Principal Awards | October 1, 2020
Equity Based Payments
Principal units (in shares)	2,940,000
KKR Holdings Principal Awards | May 1, 2021
Equity Based Payments
Principal units (in shares)	2,905,000
KKR Holdings Principal Awards | October 1, 2021
Equity Based Payments
Principal units (in shares)	3,425,000
KKR Holdings Principal Awards | October 1, 2022
Equity Based Payments
Principal units (in shares)	3,910,000