Basic and Diluted Earnings Per Share - Basic and Diluted Earnings per Common Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Earnings Per Share Disclosure [Line Items]
Net income attributable to Korn Ferry	$ 84,101	$ 51,319	$ 234,696	$ 48,264
Less: distributed and undistributed earnings to nonvested restricted stockholders	1,798	1,377	5,363	1,149
Basic net earnings attributable to common stockholders	82,303	49,942	229,333	47,115
Add: undistributed earnings to nonvested restricted stockholders	1,658	1,232	4,908	714
Less: reallocation of undistributed earnings to nonvested restricted stockholders	1,643	1,222	4,856	709
Diluted net earnings attributable to common stockholders	$ 82,318	$ 49,952	$ 229,385	$ 47,120
Basic weighted-average number of common shares outstanding	52,999	52,596	52,958	53,030
Diluted weighted-average number of common shares outstanding	53,495	53,013	53,538	53,396
Basic earnings per share	$ 1.55	$ 0.95	$ 4.33	$ 0.89
Diluted earnings per share	$ 1.54	$ 0.94	$ 4.28	$ 0.88
ESPP
Earnings Per Share Disclosure [Line Items]
Effect of dilutive securities	6	3	7	14
Restricted Stock
Earnings Per Share Disclosure [Line Items]
Effect of dilutive securities	490	414	573	352