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		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net income attributable to Lazard Ltd	$ 105,797	$ 107,209	$ 315,153	$ 317,687
Add - adjustment for earnings attributable to participating securities	(1,903)	(1,808)	(4,726)	(4,649)
Net income attributable to Lazard Ltd - basic	103,894	105,401	310,427	313,038
Add - adjustment for earnings attributable to participating securities	635	1,360	2,318	4,201
Net income attributable to Lazard Ltd - diluted	$ 104,529	$ 106,761	$ 312,745	$ 317,239
Weighted average number of shares of common stock outstanding	91,742,376	103,614,495	96,585,793	104,754,715
Add - adjustment for shares of common stock issuable on a non-contingent basis	1,533,255	1,801,248	1,575,234	1,729,937
Weighted average number of shares of common stock outstanding - basic	93,275,631	105,415,743	98,161,027	106,484,652
Weighted average number of incremental shares of common stock issuable from share-based incentive compensation	5,589,525	7,578,294	5,107,351	7,655,284
Weighted average number of shares of common stock outstanding - diluted	98,865,156	112,994,037	103,268,378	114,139,936
Net income attributable to Lazard Ltd per share of common stock:
Basic	$ 1.11	$ 1.00	$ 3.16	$ 2.94
Diluted	$ 1.06	$ 0.94	$ 3.03	$ 2.78