Net Income Per Share of Common Stock - Company's Basic and Diluted Net Income Per Share and Weighted Average Shares Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net income attributable to Lazard Ltd	$ 95,480	$ 123,178	$ 209,356	$ 210,478
Add - adjustment for earnings attributable to participating securities	(1,090)	(1,549)	(2,823)	(2,841)
Net income attributable to Lazard Ltd - basic	94,390	121,629	206,533	207,637
Add - adjustment for earnings attributable to participating securities	554	1,549	1,683	2,841
Net income attributable to Lazard Ltd - diluted	$ 94,944	$ 123,178	$ 208,216	$ 210,478
Weighted average number of shares of common stock outstanding	97,380,282	105,104,377	99,007,501	105,324,825
Add - adjustment for shares of common stock issuable on a non-contingent basis	1,279,891	1,642,277	1,596,223	1,694,282
Weighted average number of shares of common stock outstanding - basic	98,660,173	106,746,654	100,603,724	107,019,107
Weighted average number of incremental shares of common stock issuable from share-based incentive compensation	4,093,163	6,856,824	4,866,264	7,693,778
Weighted average number of shares of common stock outstanding - diluted	102,753,336	113,603,478	105,469,988	114,712,885
Net income attributable to Lazard Ltd per share of common stock:
Basic	$ 0.96	$ 1.14	$ 2.05	$ 1.94
Diluted	$ 0.92	$ 1.08	$ 1.97	$ 1.83