EQUITY AND REDEEMABLE INTEREST - Common Stock (Details) - USD ($)				9 Months Ended
	Apr. 08, 2021	Apr. 06, 2021	Apr. 05, 2021	Sep. 30, 2021	Feb. 28, 2021	Dec. 31, 2020	Sep. 30, 2020
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)				259,631,180
Issuance of stock (in shares)				24,393,407
Stock option exercises, net of shares withheld for tax (in shares)				1,460,388
Vesting of restricted stock awards, net of shares withheld for tax (in shares)				4,448,648
Ending balance (in shares)				289,875,333
Private Placement
Class of Stock [Line Items]
Proceeds from sale of shares			$ 250,000,000
Proceeds from issuance of stock	$ 250,000,000
Underwritten
Class of Stock [Line Items]
Proceeds from issuance of stock	578,200,000
Fees related to stock issuance	$ 700,000
Ares Operating Group
Increase (Decrease) in Stockholders' Equity
Exchanges of AOG units (in shares)				0
Redemptions of AOG Units (in shares)				(58,290)
Class A Common Stock
Class of Stock [Line Items]
Common stock, par value (in dollars per share)				$ 0.01		$ 0.01
Authorized amount					$ 150,000,000
Stock repurchase program, number of shares repurchased (in shares)				0			0
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)				147,182,562
Issuance of stock (in shares)				12,159,200
Stock option exercises, net of shares withheld for tax (in shares)				1,460,388
Vesting of restricted stock awards, net of shares withheld for tax (in shares)				4,448,648
Ending balance (in shares)				167,581,165
Class A Common Stock | Private Placement
Class of Stock [Line Items]
Number of shares sold (in shares)			1,234,200
Class A Common Stock | Underwritten
Class of Stock [Line Items]
Number of shares sold (in shares)		10,925,000
Number of shares sold to underwriters (in shares)		1,425,000
Class A Common Stock | Ares Operating Group
Increase (Decrease) in Stockholders' Equity
Exchanges of AOG units (in shares)				2,330,367
Redemptions of AOG Units (in shares)				0
Non- voting Common Stock
Class of Stock [Line Items]
Common stock, par value (in dollars per share)				$ 0.01		0.01
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)				0
Issuance of stock (in shares)				3,489,911
Stock option exercises, net of shares withheld for tax (in shares)				0
Vesting of restricted stock awards, net of shares withheld for tax (in shares)				0
Ending balance (in shares)				3,489,911
Non- voting Common Stock | Private Placement
Class of Stock [Line Items]
Number of shares sold (in shares)			3,489,911
Non- voting Common Stock | Ares Operating Group
Increase (Decrease) in Stockholders' Equity
Exchanges of AOG units (in shares)				0
Redemptions of AOG Units (in shares)				0
Class B Common Stock
Class of Stock [Line Items]
Common stock, par value (in dollars per share)				$ 0.01		0.01
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)				1,000
Issuance of stock (in shares)				0
Stock option exercises, net of shares withheld for tax (in shares)				0
Vesting of restricted stock awards, net of shares withheld for tax (in shares)				0
Ending balance (in shares)				1,000
Class B Common Stock | Ares Operating Group
Increase (Decrease) in Stockholders' Equity
Exchanges of AOG units (in shares)				0
Redemptions of AOG Units (in shares)				0
Class C Common Stock
Class of Stock [Line Items]
Common stock, par value (in dollars per share)				$ 0.01		$ 0.01
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)				112,447,618
Issuance of stock (in shares)				8,744,296
Stock option exercises, net of shares withheld for tax (in shares)				0
Vesting of restricted stock awards, net of shares withheld for tax (in shares)				0
Ending balance (in shares)				118,803,257
Class C Common Stock | Ares Operating Group
Increase (Decrease) in Stockholders' Equity
Exchanges of AOG units (in shares)				(2,330,367)
Redemptions of AOG Units (in shares)				(58,290)