Consolidated Quarterly Data (Unaudited) -Schedule of Quarterly Financial Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 31,803	$ 27,450	$ 31,185	$ 26,683	$ 28,990	$ 21,574	$ 25,962	$ 26,321	$ 117,121	$ 102,847	$ 100,003
Gross profit	6,779	5,009	5,227	5,243	7,352	3,771	3,845	4,188	22,258	19,156	19,284
Net earnings	1,404	782	807	688	1,814	34	(156)	108	3,681	1,800	2,098
Less: net earnings (loss) attributable to the noncontrolling interest	187	238	158	54	558	156	(31)	86	637	769	248
Net earnings (loss) attributable to Kewaunee Scientific Corporation	$ 1,217	$ 544	$ 649	$ 634	$ 1,256	$ (122)	$ (125)	$ 22	$ 3,044	$ 1,031	$ 1,850
Net earnings (loss) per share attributable to Kewaunee Scientific Corporation
Basic	$ 0.47	$ 0.21	$ 0.25	$ 0.25	$ 0.49	$ (0.05)	$ (0.05)	$ 0.01	$ 1.18	$ 0.40	$ 0.72
Diluted	$ 0.46	$ 0.21	$ 0.25	$ 0.25	$ 0.49	$ (0.05)	$ (0.05)	$ 0.01	$ 1.17	$ 0.40	$ 0.72
Cash dividends per share	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10