Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)				3 Months Ended		9 Months Ended
		Sep. 24, 2018	Mar. 15, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3				$ 5,800,000		$ 21,800,000	$ 64,300,000
Gross transfers out of Level 3				$ 1,500,000		16,400,000	210,600,000
All Investment Issuers Other Than Ares
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3					$ 0		5,600,000
Gross transfers out of Level 3					200,000		153,700,000
Other Asset Backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers out of Level 3						12,100,000
Foreign corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3						14,700,000
Gross transfers out of Level 3						1,600,000	200,000
U.S. corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3						1,300,000	1,200,000
Gross transfers out of Level 3						$ 2,700,000	1,300,000
Common Stock | Ares | Insurance Segment
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 1		$ 56,900,000	$ 208,200,000
Other invested assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3	[1]						58,700,000
Gross transfers out of Level 3	[1]						56,900,000
Other invested assets | Limited partnership interests in certain subsidiaries of Ares | Insurance Segment
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3			$ 58,700,000				58,700,000
Gross transfers out of Level 3		$ 56,900,000			$ 56,900,000		56,900,000
Preferred Stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers into Level 3							4,400,000
RMBS
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gross transfers out of Level 3							$ 150,600,000

[1] Includes partnership and non-marketable equity investments accounted for at fair value.