Cover - shares	6 Months Ended
	Jun. 30, 2024	Jul. 26, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	0-25837
Entity Registrant Name	HEIDRICK & STRUGGLES INTERNATIONAL, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-2681268
Entity Address, Address Line One	233 South Wacker Drive
Entity Address, Address Line Two	Suite 4900
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60606-6303
City Area Code	(312)
Local Phone Number	496-1200
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	HSII
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		20,317,376
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001066605
Current Fiscal Year End Date	--12-31