Segments - Financial Highlights by Operating Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 346,883	$ 496,198
Net (loss) income attributable to Korn Ferry	(30,833)	42,951
Net (loss) income attributable to noncontrolling interest	(22)	699
Other income, net	(11,162)	(1,826)
Interest expense, net	6,894	4,057
Income tax (benefit) provision	(8,672)	14,453
Operating (loss) income	(43,795)	60,334
Depreciation and amortization	15,035	12,777
Other income (loss), net	11,162	1,826
EBITDA	(17,598)
Integration/acquisition costs	737
Restructuring charges, net	27,487
Adjusted EBITDA	10,626
EBITDA and Adjusted EBITDA		74,937
Fee Revenue
Segment Reporting Information [Line Items]
Total revenue	344,097	484,549
Operating Segments | Consulting
Segment Reporting Information [Line Items]
Total revenue	99,590	141,336
Operating (loss) income	(10,927)	11,783
Depreciation and amortization	4,009	4,414
Other income (loss), net	788	525
EBITDA	(6,130)
Restructuring charges, net	12,734
Adjusted EBITDA	6,604
EBITDA and Adjusted EBITDA		16,722
Operating Segments | Digital
Segment Reporting Information [Line Items]
Total revenue	56,022	57,984
Operating (loss) income	(2,627)	14,008
Depreciation and amortization	6,726	3,639
Other income (loss), net	418	201
EBITDA	4,517
Integration/acquisition costs	556
Restructuring charges, net	2,870
Adjusted EBITDA	7,943
EBITDA and Adjusted EBITDA		17,848
Operating Segments | Executive Search
Segment Reporting Information [Line Items]
Total revenue	120,886	198,013
Operating (loss) income	(12,310)	45,636
Depreciation and amortization	1,569	2,031
Other income (loss), net	9,635	1,224
EBITDA	(1,106)
Restructuring charges, net	9,160
Adjusted EBITDA	8,054
EBITDA and Adjusted EBITDA		48,891
Operating Segments | Executive Search | North America
Segment Reporting Information [Line Items]
Total revenue	69,856	115,446
Operating (loss) income	(5,735)	30,322
Depreciation and amortization	730	901
Other income (loss), net	9,342	1,140
EBITDA	4,337
Restructuring charges, net	975
Adjusted EBITDA	5,312
EBITDA and Adjusted EBITDA		32,363
Operating Segments | Executive Search | EMEA
Segment Reporting Information [Line Items]
Total revenue	30,195	47,312
Operating (loss) income	(6,219)	7,311
Depreciation and amortization	362	456
Other income (loss), net	19	12
EBITDA	(5,838)
Restructuring charges, net	7,548
Adjusted EBITDA	1,710
EBITDA and Adjusted EBITDA		7,779
Operating Segments | Executive Search | Asia Pacific
Segment Reporting Information [Line Items]
Total revenue	17,340	27,668
Operating (loss) income	861	6,993
Depreciation and amortization	275	346
Other income (loss), net	226	15
EBITDA	1,362
Restructuring charges, net	232
Adjusted EBITDA	1,594
EBITDA and Adjusted EBITDA		7,354
Operating Segments | Executive Search | Latin America
Segment Reporting Information [Line Items]
Total revenue	3,495	7,587
Operating (loss) income	(1,217)	1,010
Depreciation and amortization	202	328
Other income (loss), net	48	57
EBITDA	(967)
Restructuring charges, net	405
Adjusted EBITDA	(562)
EBITDA and Adjusted EBITDA		1,395
Operating Segments | RPO & Professional Search
Segment Reporting Information [Line Items]
Total revenue	70,385	98,865
Operating (loss) income	2,165	15,041
Depreciation and amortization	940	992
Other income (loss), net	196	74
EBITDA	3,301
Restructuring charges, net	2,723
Adjusted EBITDA	6,024
EBITDA and Adjusted EBITDA		16,107
Operating Segments | Fee Revenue | Consulting
Segment Reporting Information [Line Items]
Total revenue	99,318	137,542
Operating Segments | Fee Revenue | Digital
Segment Reporting Information [Line Items]
Total revenue	55,973	57,984
Operating Segments | Fee Revenue | Executive Search
Segment Reporting Information [Line Items]
Total revenue	120,143	193,199
Operating Segments | Fee Revenue | Executive Search | North America
Segment Reporting Information [Line Items]
Total revenue	69,315	111,722
Operating Segments | Fee Revenue | Executive Search | EMEA
Segment Reporting Information [Line Items]
Total revenue	30,081	46,530
Operating Segments | Fee Revenue | Executive Search | Asia Pacific
Segment Reporting Information [Line Items]
Total revenue	17,252	27,362
Operating Segments | Fee Revenue | Executive Search | Latin America
Segment Reporting Information [Line Items]
Total revenue	3,495	7,585
Operating Segments | Fee Revenue | RPO & Professional Search
Segment Reporting Information [Line Items]
Total revenue	68,663	95,824
Corporate
Segment Reporting Information [Line Items]
Operating (loss) income	(20,096)	(26,134)
Depreciation and amortization	1,791	1,701
Other income (loss), net	125	(198)
EBITDA	(18,180)
Integration/acquisition costs	181
Adjusted EBITDA	$ (17,999)
EBITDA and Adjusted EBITDA		$ (24,631)