Basic and Diluted Earnings Per Share - Schedule of Basic and Diluted Earnings per Common Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2025	Oct. 31, 2024
Earnings Per Share Disclosure [Line Items]
Net income attributable to Korn Ferry	$ 72,399	$ 60,800	$ 139,035	$ 123,404
Less: distributed and undistributed earnings to nonvested restricted stockholders	876	766	1,729	1,770
Basic net earnings attributable to common stockholders	71,523	60,034	137,306	121,634
Add: undistributed earnings to nonvested restricted stockholders	574	518	1,042	1,174
Less: reallocation of undistributed earnings to nonvested restricted stockholders	565	510	1,024	1,154
Diluted net earnings attributable to common stockholders	$ 71,532	$ 60,042	$ 137,324	$ 121,654
Weighted-average common shares outstanding:
Basic weighted-average number of common shares outstanding (in shares)	51,745	51,957	51,606	51,953
Diluted weighted-average number of common shares outstanding (in shares)	52,517	52,750	52,557	52,864
Net earnings per common share:
Basic earnings per share (in usd per share)	$ 1.38	$ 1.16	$ 2.66	$ 2.34
Diluted earnings per share (in usd per share)	$ 1.36	$ 1.14	$ 2.61	$ 2.30
Employee Stock Purchase Plan ("ESPP")
Weighted-average common shares outstanding:
Effect of dilutive securities (in shares)	6	3	8	2
Restricted Stock Awards
Weighted-average common shares outstanding:
Effect of dilutive securities (in shares)	766	790	943	909