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Senior Debt - Senior Debt (Details) - USD ($)		1 Months Ended	12 Months Ended
Senior Debt - Senior Debt (Details) - USD ($)	Dec. 12, 2024	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Principal			$ 1,700,000,000	$ 1,700,000,000
Unamortized Debt Costs			12,948,000	9,800,000
Carrying Value			1,687,052,000	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			0.00%
Principal			$ 0	400,000,000
Unamortized Debt Costs			0	531,000
Carrying Value			0	399,469,000
Aggregate principal amount of debt purchased	$ 164,347,000	$ 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			3.81%
Principal			$ 300,000,000	300,000,000
Unamortized Debt Costs			1,213,000	1,235,000
Carrying Value			298,787,000	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			4.70%
Principal			$ 500,000,000	500,000,000
Unamortized Debt Costs			3,783,000	4,012,000
Carrying Value			496,217,000	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			4.56%
Principal			$ 500,000,000	500,000,000
Unamortized Debt Costs			3,875,000	4,022,000
Carrying Value			496,125,000	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			6.16%
Principal			$ 400,000,000	0
Unamortized Debt Costs			4,077,000	0
Carrying Value			$ 395,923,000	$ 0