Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Apr. 30, 2020	$ 38,415	$ 6,885	$ 3,360	$ (53)	$ 37,821	$ (9,598)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(598)				(598)
Other comprehensive loss	(13)					(13)
Stock-based compensation	98	20	78
Ending balance at Jul. 31, 2020	37,902	6,905	3,438	(53)	37,223	(9,611)
Beginning balance at Apr. 30, 2020	38,415	6,885	3,360	(53)	37,821	(9,598)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(697)
Other comprehensive loss	(17)
Ending balance at Jan. 31, 2021	38,055	6,915	3,684	(53)	37,124	(9,615)
Beginning balance at Jul. 31, 2020	37,902	6,905	3,438	(53)	37,223	(9,611)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(180)				(180)
Other comprehensive loss	(35)					(35)
Stock-based compensation	143	0	143
Ending balance at Oct. 31, 2020	37,830	6,905	3,581	(53)	37,043	(9,646)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	81				81
Other comprehensive loss	31					31
Stock-based compensation	113	10	103
Ending balance at Jan. 31, 2021	38,055	6,915	3,684	(53)	37,124	(9,615)
Beginning balance at Apr. 30, 2021	41,241	6,915	3,807	(53)	34,149	(3,577)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(1,345)				(1,345)
Other comprehensive loss	(76)					(76)
Stock-based compensation	238	67	171
Ending balance at Jul. 31, 2021	40,058	6,982	3,978	(53)	32,804	(3,653)
Beginning balance at Apr. 30, 2021	41,241	6,915	3,807	(53)	34,149	(3,577)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(5,764)
Other comprehensive loss	(107)
Ending balance at Jan. 31, 2022	35,847	6,983	4,216	(53)	28,385	(3,684)
Beginning balance at Jul. 31, 2021	40,058	6,982	3,978	(53)	32,804	(3,653)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(3,100)				(3,100)
Other comprehensive loss	(83)					(83)
Stock-based compensation	130	1	129
Ending balance at Oct. 31, 2021	37,005	6,983	4,107	(53)	29,704	(3,736)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Kewaunee Scientific Corporation	(1,319)				(1,319)
Other comprehensive loss	52					52
Stock-based compensation	109		109
Ending balance at Jan. 31, 2022	$ 35,847	$ 6,983	$ 4,216	$ (53)	$ 28,385	$ (3,684)