Quarterly Results - Schedule of Unaudited Quarterly Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2021	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Quarterly Financial Information [Line Items]
Fee Revenue									$ 1,819,946	$ 1,977,330	$ 1,973,862
Operating income (loss)	$ 86,252	$ 65,155	$ 48,172	$ (43,795)	$ 22,227	$ 31,595	$ 61,869	$ 60,334	155,784	176,025	140,826
Net income	66,751	51,588	28,078	(30,855)	(621)	20,956	43,032	43,650	115,562	107,017	104,796
Net income attributable to Korn Ferry	$ 66,190	$ 51,319	$ 27,778	$ (30,833)	$ (802)	$ 19,993	$ 42,804	$ 42,951	$ 114,454	$ 104,946	$ 102,651
Earnings per common share attributable to Korn Ferry:
Basic	$ 1.22	$ 0.95	$ 0.51	$ (0.58)	$ (0.02)	$ 0.37	$ 0.78	$ 0.77	$ 2.11	$ 1.91	$ 1.84
Diluted	$ 1.21	$ 0.94	$ 0.51	$ (0.58)	$ (0.02)	$ 0.36	$ 0.77	$ 0.76	$ 2.09	$ 1.90	$ 1.81
Fee Revenue
Quarterly Financial Information [Line Items]
Fee Revenue	$ 555,151	$ 475,360	$ 435,439	$ 344,097	$ 440,469	$ 515,325	$ 492,389	$ 484,549	$ 1,810,047	$ 1,932,732	$ 1,926,033