Segments - Financial Highlights by Operating Segment (Detail) - USD ($) $ 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
Segment Reporting Information [Line Items]
Total revenue									$ 1,819,946		$ 1,977,330		$ 1,973,862
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
Net income attributable to noncontrolling interest									1,108		2,071		2,145
Other loss (income), net									(37,194)		2,879		(10,405)
Interest expense, net									29,278		22,184		16,891
Income tax provision									48,138		43,945		29,544
Operating income	86,252	65,155	48,172	(43,795)	22,227	31,595	61,869	60,334	155,784		176,025		140,826
Depreciation and amortization									61,845		55,311		46,489
Other income (loss), net									37,194		(2,879)		10,405
Integration/acquisition costs									737		12,152		6,746
Tradename write-offs													106,555
Restructuring charges, net									30,732		58,559
Separation Costs											1,783
Adjusted EBITDA									286,292	[1]	300,951	[2]	311,021	[3]
Fee Revenue
Segment Reporting Information [Line Items]
Total 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
Operating Segments | Consulting
Segment Reporting Information [Line Items]
Total revenue									517,046		557,255		585,893
Adjusted EBITDA									81,522	[1]	61,092	[2]	66,531	[3]
Operating Segments | Digital
Segment Reporting Information [Line Items]
Total revenue									287,780		294,261		252,727
Adjusted EBITDA									86,095	[1]	83,073	[2]	84,455	[3]
Operating Segments | Executive Search | North America
Segment Reporting Information [Line Items]
Total revenue									399,104		447,528		469,743
Adjusted EBITDA									98,099	[1]	120,725	[2]	131,343	[3]
Operating Segments | Executive Search | EMEA
Segment Reporting Information [Line Items]
Total revenue									139,213		172,978		186,131
Adjusted EBITDA									11,742	[1]	31,067	[2]	31,660	[3]
Operating Segments | Executive Search | Asia Pacific
Segment Reporting Information [Line Items]
Total revenue									83,463		99,209		105,543
Adjusted EBITDA									16,676	[1]	22,885	[2]	26,073	[3]
Operating Segments | Executive Search | Latin America
Segment Reporting Information [Line Items]
Total revenue									17,500		29,493		31,960
Adjusted EBITDA									1,289	[1]	6,402	[2]	4,730	[3]
Operating Segments | RPO & Professional Search
Segment Reporting Information [Line Items]
Total revenue									375,840		376,606		341,865
Adjusted EBITDA									69,411	[1]	60,168	[2]	54,407	[3]
Operating Segments | Fee Revenue | Consulting
Segment Reporting Information [Line Items]
Total revenue									515,844		543,095		568,321
Operating Segments | Fee Revenue | Digital
Segment Reporting Information [Line Items]
Total revenue									287,306		292,366		252,727
Operating Segments | Fee Revenue | Executive Search | North America
Segment Reporting Information [Line Items]
Total revenue									397,275		434,624		455,826
Operating Segments | Fee Revenue | Executive Search | EMEA
Segment Reporting Information [Line Items]
Total revenue									138,954		170,314		182,829
Operating Segments | Fee Revenue | Executive Search | Asia Pacific
Segment Reporting Information [Line Items]
Total revenue									83,306		98,132		104,291
Operating Segments | Fee Revenue | Executive Search | Latin America
Segment Reporting Information [Line Items]
Total revenue									17,500		29,400		31,896
Operating Segments | Fee Revenue | RPO & Professional Search
Segment Reporting Information [Line Items]
Total revenue									369,862		364,801		330,143
Corporate
Segment Reporting Information [Line Items]
Adjusted EBITDA									$ (78,542)	[1]	$ (84,461)	[2]	$ (88,178)	[3]

[1] ^{Adjusted EBITDA refers to earnings before interest, taxes, depreciation and amortization and further excludes integration/acquisition and net restructuring charges.}

[2] ^{Adjusted EBITDA refers to earnings before interest, taxes, depreciation and amortization and further excludes integration/acquisition costs, net restructuring charges and separation costs.}

[3] ^{Adjusted EBITDA refers to earnings before interest, taxes, depreciation and amortization and further excludes, integration/acquisition costs and tradename write-offs}