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Charge to retained earnings pertaining to issuance of restricted stock units in connection with participation rights.

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Dividend participation rights issued relating to restricted stock.

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Issuance of restricted stock units in connection with dividend participation rights.

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Percentage of outstanding shares available under an equity-based compensation award plan.

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Share based compensation arrangement by share based payment award target shares earned description.

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Number of shares granted to directors under the Directors Fee deferral unit plan.

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Description of basis for conversion of convertible common stock.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Incentive Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended
	Apr. 29, 2021	Apr. 24, 2018	Mar. 31, 2022	Mar. 31, 2021
Lazard Fund Interests [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense, years			1 year
Non-Executive [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of annual compensation received by directors in the form of DSUs			55.00%
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock conversion basis			one-for-one
Grant date fair value, amortized periods			generally, one-third after two years and the remaining two-thirds after the third year
Number of dividend participation rights issued			106,885
Charges to retained earnings, net of estimated forfeitures			$ 3,690
Weighted-average grant date fair value of awards granted			$ 33.09	$ 43.13
Unrecognized compensation expense			$ 181,224
Unrecognized compensation expense, years			1 year
DSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of awards granted			$ 37.95	41.92
DSUs [Member] \| Non-Executive [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted under the directors deferred unit plan			3,929
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of awards granted			$ 33.17	43.23
Unrecognized compensation expense			$ 41,775
Unrecognized compensation expense, years			1 year
Dividend participation rights issued			8,948
Charges to retained earnings, net of estimated forfeitures			$ 313
PRSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of awards granted			$ 35.44	46.63
Unrecognized compensation expense			$ 4,510
Unrecognized compensation expense, years			1 year 3 months 18 days
Descriptions of vesting period			PRSUs will vest on a single date approximately three years following the date of the grant
Vesting period			3 years
PRSUs target share distribution for Class A common stock, description			The target number of shares of common stock subject to each PRSU is one; however, based on the achievement of the performance criteria, the number of shares of common stock that may be received in connection with each PRSU generally can range from zero to two times the target number for awards granted prior to February 2021. For awards granted beginning in February 2021, based on both the performance-based and market-based criteria, the number of shares of common stock can range from zero to 2.4 times the target number.
Profits Interest Participation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock conversion basis			one-for-one
Weighted-average grant date fair value of awards granted			$ 34.53	$ 44.73
Unrecognized compensation expense			$ 74,580
Unrecognized compensation expense, years			8 months 12 days
Descriptions of vesting period			Profits interest participation rights generally provide for vesting approximately three years following the grant date
Vesting period			3 years
PRSUs target share distribution for Class A common stock, description			The target number of shares of common stock subject to each PRPU is one. Based on the achievement of performance criteria, as determined by the Compensation Committee, the number of shares of common stock that may be received in connection with the PRPU awards granted in February 2019 and February 2020 will range from zero to two times the target number. For the PRPU awards granted beginning in February 2021, subject to both performance-based and incremental market-based criteria, the number of shares will range from zero to 2.4 times the target number.
Percentage of target number of shares subject to the applicable units no longer subject to forfeiture due to threshold level of performance being achieved			25.00%
Common Stock [Member] \| RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Withholding taxes in lieu of share delivery			1,490,239
Delivery of common stock associated with stock awards			2,276,767
Common Stock [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Withholding taxes in lieu of share delivery			131,069
Delivery of common stock associated with stock awards			213,290
Common Stock [Member] \| 2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized pertaining to share based compensation arrangements		30,000,000
Share-based compensation arrangement by share-based payment award, number of additional shares authorized	20,000,000
Common Stock [Member] \| Awarded Under 2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of outstanding common stock available under the plan		30.00%
Compensation plan expiration period		Apr. 24, 2018
Common Stock [Member] \| 2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized pertaining to share based compensation arrangements			25,000,000