Investments - Company's Investments and Securities Sold, Not Yet Purchased (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Investments	$ 698,977	$ 1,007,339
Alternative Investment Funds [Member]
Schedule of Investments [Line Items]
Investments	56,947	49,757
Alternative Investment Funds [Member] | Lazard Fund Interests [Member] | Lazard Group LLC [Member]
Schedule of Investments [Line Items]
Investments	24,137	18,326
Debt Funds [Member]
Schedule of Investments [Line Items]
Investments	178,556	164,952
Debt Funds [Member] | Lazard Fund Interests [Member] | Lazard Group LLC [Member]
Schedule of Investments [Line Items]
Investments	142,632	132,875
Equity Funds [Member]
Schedule of Investments [Line Items]
Investments	350,282	375,761
Equity Funds [Member] | Lazard Fund Interests [Member] | Lazard Group LLC [Member]
Schedule of Investments [Line Items]
Investments	$ 266,528	$ 306,618