Industry Segments - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 27,881	$ 28,210	$ 55,159	$ 55,593
Operating income (loss)	631	843	1,516	1,640
Capital expenditures	45	128	163	238
Capitalized software	126	605	371	1,890
Depreciation and amortization	1,514	2,183	3,194	4,428
Earnings (loss) before income taxes	589	1,555	2,806	2,877
Supply Chain Management
Segment Reporting Information [Line Items]
Revenues	22,297	23,487	44,033	45,834
Operating income (loss)	3,983	4,360	8,087	8,211
Capital expenditures	45	44	84	75
Capitalized software	126	605	371	1,890
Depreciation and amortization	1,415	2,089	3,001	4,241
Earnings (loss) before income taxes	3,845	4,480	8,220	8,516
IT Consulting
Segment Reporting Information [Line Items]
Revenues	5,033	4,158	10,059	8,536
Operating income (loss)	103	(12)	209	166
Capital expenditures	0	0	0	0
Capitalized software	0	0	0	0
Depreciation and amortization	0	1	1	3
Earnings (loss) before income taxes	103	(12)	207	166
Other
Segment Reporting Information [Line Items]
Revenues	551	565	1,067	1,223
Operating income (loss)	(3,455)	(3,505)	(6,780)	(6,737)
Capital expenditures	0	84	79	163
Capitalized software	0	0	0	0
Depreciation and amortization	99	93	192	184
Earnings (loss) before income taxes	$ (3,359)	$ (2,913)	$ (5,621)	$ (5,805)