SENIOR DEBT - Senior Debt (Details) - USD ($)	1 Months Ended	9 Months Ended
	Mar. 31, 2024	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Principal		$ 1,864,347,000	$ 1,700,000,000
Unamortized Debt Costs		11,504,000	9,800,000
Carrying Value		1,852,843,000	1,690,200,000
Lazard Group 2025 Senior Notes
Debt Instrument [Line Items]
Initial Principal Amount		$ 400,000,000
Maturity Date		Feb. 13, 2025
Annual Interest Rate		3.75%
Effective Interest Rate		3.77%
Principal		$ 164,347,000	400,000,000
Unamortized Debt Costs		72,000	531,000
Carrying Value		164,275,000	399,469,000
Aggregate principal amount of debt purchased	$ 235,653,000
Lazard Group 2027 Senior Notes
Debt Instrument [Line Items]
Initial Principal Amount		$ 300,000,000
Maturity Date		Mar. 01, 2027
Annual Interest Rate		3.625%
Effective Interest Rate		3.76%
Principal		$ 300,000,000	300,000,000
Unamortized Debt Costs		943,000	1,235,000
Carrying Value		299,057,000	298,765,000
Lazard Group 2028 Senior Notes
Debt Instrument [Line Items]
Initial Principal Amount		$ 500,000,000
Maturity Date		Sep. 19, 2028
Annual Interest Rate		4.50%
Effective Interest Rate		4.67%
Principal		$ 500,000,000	500,000,000
Unamortized Debt Costs		3,373,000	4,012,000
Carrying Value		496,627,000	495,988,000
Lazard Group 2029 Senior Notes
Debt Instrument [Line Items]
Initial Principal Amount		$ 500,000,000
Maturity Date		Mar. 11, 2029
Annual Interest Rate		4.375%
Effective Interest Rate		4.53%
Principal		$ 500,000,000	500,000,000
Unamortized Debt Costs		3,442,000	4,022,000
Carrying Value		496,558,000	495,978,000
Lazard Group 2031 Senior Notes
Debt Instrument [Line Items]
Initial Principal Amount	$ 400,000,000	$ 400,000,000
Maturity Date		Mar. 15, 2031
Annual Interest Rate	6.00%	6.00%
Effective Interest Rate		6.14%
Principal		$ 400,000,000	0
Unamortized Debt Costs		3,674,000	0
Carrying Value		$ 396,326,000	$ 0