Face (par) amount of debt instrument at time of issuance.

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-Publisher FASB

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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-Name Regulation S-X (SX)

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Date the credit facility terminates, in CCYY-MM-DD format.

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The effective interest rate during the reporting period.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Senior Debt - Senior Debt (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Nov. 30, 2013	Dec. 31, 2013	Sep. 25, 2012
Debt Instrument [Line Items]
Senior Debt, Outstanding	$ 1,048,350us-gaap_SeniorNotes		$ 1,048,350us-gaap_SeniorNotes
Revolving Credit Facility, Initial Principal Amount				150,000
Lazard Group 6.85% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Debt, Outstanding	548,350		548,350
Senior Debt, Maturity Date	Jun. 15, 2017
Senior Debt, Initial Principal Amount	600,000
Senior Debt, Annual Interest Rate	6.85%
Lazard Group 4.25% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Debt, Outstanding	500,000		500,000
Senior Debt, Maturity Date	Nov. 14, 2020
Senior Debt, Initial Principal Amount	500,000	500,000
Senior Debt, Annual Interest Rate	4.25%	4.25%
Lazard Group Credit Facility [Member]
Debt Instrument [Line Items]
Senior Debt, Outstanding
Revolving Credit Facility, Initial Principal Amount	$ 150,000
Credit Facility, Expiration Date	Sep. 25, 2015
Revolving Credit Facility, Annual Interest Rate	0.78%
Lazard Group 7.125% Senior Notes [Member]
Debt Instrument [Line Items]
Senior Debt, Maturity Date		May 15, 2015
Senior Debt, Annual Interest Rate		7.125%