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INCENTIVE PLANS - Additional Information (Details) $ / shares in Units, $ in Thousands			9 Months Ended
	Apr. 29, 2021 shares	Apr. 24, 2018 shares	Sep. 30, 2023 USD ($) d $ / shares shares	Sep. 30, 2022 $ / shares	Aug. 31, 2023 tranche	Feb. 01, 2021	Jan. 31, 2021
Lazard Fund Interests
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense (in years)			10 months 24 days
Non-Executive
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual compensation received by directors in the form of DSUs (as percent)			55.00%
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock conversion basis			one-for-one
Number of dividend participation rights issued			515,420
Charges to retained earnings, net of estimated forfeitures | $			$ 16,736
Units granted (in shares)			5,496,350
Weighted average grant date fair value, granted (in USD per share) | $ / shares			$ 36.51	$ 33.64
Unrecognized compensation expense | $			$ 156,284
Unrecognized compensation expense (in years)			1 year
RSUs | Three Years Following Date of Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
RSUs | Five Years Following Date of Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			66.67%
DSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in shares)			58,414
Weighted average grant date fair value, granted (in USD per share) | $ / shares			$ 29.87	35.53
DSUs | Non-Executive
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in shares)			43,999
Units granted under the directors deferred unit plan (in shares)			14,415
RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in shares)			646,979
Weighted average grant date fair value, granted (in USD per share) | $ / shares			$ 37.65	33.31
Dividend participation rights issued (in shares)			71,900
Net of estimated forfeitures | $			$ 2,358
Unrecognized compensation expense | $			$ 20,050
Unrecognized compensation expense (in years)			10 months 24 days
PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, granted (in USD per share) | $ / shares				35.44
Unrecognized compensation expense | $			$ 1,754
Unrecognized compensation expense (in years)			6 months
Vesting period			3 years
PRSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target number of shares, multiplier			0
PRSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target number of shares, multiplier			2.4
SPRPUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in shares)			2,250,000
Weighted average grant date fair value, granted (in USD per share) | $ / shares			$ 15.06
Award vesting, number of tranches | tranche					3
Common stock price, number of consecutive days | d			30
SPRPUs | Scenario, Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested in period, fair value | $			$ 33,900
SPRPUs | Three Years Following Date of Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			20.00%
Common stock price, appreciation (as a percent)			25.00%
SPRPUs | Five Years Following Date of Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			40.00%
Common stock price, appreciation (as a percent)			50.00%
SPRPUs | Seven Years Following Date of Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock price, appreciation (as a percent)			100.00%
Profits Interest Participation Rights Excluding SPRPUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years
Profits Interest Participation Rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock conversion basis			one-for-one
Units granted (in shares)			3,488,074
Weighted average grant date fair value, granted (in USD per share) | $ / shares			$ 22.47	$ 34.53
Unrecognized compensation expense | $			$ 57,590
Unrecognized compensation expense (in years)			1 year 10 months 24 days
PRPUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in shares)			0
PRPUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target number of shares, multiplier						0	0
PRPUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target number of shares, multiplier						2.4	2
Common Stock | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Withholding taxes in lieu of share delivery (in shares)			1,204,403
Delivery of common stock associated with stock awards (in shares)			2,155,547
Common Stock | RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Withholding taxes in lieu of share delivery (in shares)			268,402
Delivery of common stock associated with stock awards (in shares)			391,880
2018 Equity Incentive Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares authorized (in shares)	20,000,000
Common stock shares authorized (in shares)		30,000,000
Awarded Under 2008 Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding common stock available (as percent)		30.00%
Compensation plan expiration period		Apr. 24, 2018
2005 Equity Incentive Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares authorized (in shares)			25,000,000

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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- Definition

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+ References

No definition available.

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