Basic and Diluted Earnings (Loss) Per Share - Basic and Diluted Earnings (Loss) per Common Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2024	Oct. 31, 2023	Oct. 31, 2024	Oct. 31, 2023
Earnings Per Share Disclosure [Line Items]
Net income (loss) attributable to Korn Ferry	$ 60,800	$ (1,711)	$ 123,404	$ 44,894
Less: distributed and undistributed earnings to nonvested restricted stockholders	766	169	1,770	843
Basic net earnings (loss) attributable to common stockholders	60,034	(1,880)	121,634	44,051
Add: undistributed earnings to nonvested restricted stockholders	518	0	1,174	459
Less: reallocation of undistributed earnings to nonvested restricted stockholders	510	0	1,154	457
Diluted net earnings (loss) attributable to common stockholders	$ 60,042	$ (1,880)	$ 121,654	$ 44,053
Weighted-average common shares outstanding:
Basic weighted-average number of common shares outstanding (in shares)	51,957	51,328	51,953	51,131
Diluted weighted-average number of common shares outstanding (in shares)	52,750	51,328	52,864	51,401
Net earnings (loss) per common share:
Basic earnings (loss) per share (in usd per share)	$ 1.16	$ (0.04)	$ 2.34	$ 0.86
Diluted earnings (loss) per share (in usd per share)	$ 1.14	$ (0.04)	$ 2.30	$ 0.86
ESPP
Weighted-average common shares outstanding:
Effect of dilutive securities (in shares)	3	0	2	8
Restricted Stock Awards
Weighted-average common shares outstanding:
Effect of dilutive securities (in shares)	790	0	909	262