Industry Segments - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Segment Reporting Information [Line Items]
Revenues	$ 28,210	$ 28,033	$ 55,593	$ 55,432
Operating income (loss)	843	1,526	1,640	2,133
Capital expenditures	128	180	238	894
Capitalized software	605	1,204	1,890	2,088
Depreciation and amortization	2,183	1,913	4,428	3,711
Earnings (loss) before income taxes	1,555	1,336	2,877	2,696
Supply Chain Management
Segment Reporting Information [Line Items]
Revenues	23,487	22,114	45,834	43,572
Operating income (loss)	4,360	3,973	8,211	7,040
Capital expenditures	44	52	75	124
Capitalized software	605	1,204	1,890	2,088
Depreciation and amortization	2,089	1,828	4,241	3,554
Earnings (loss) before income taxes	4,480	4,008	8,516	7,058
IT Consulting
Segment Reporting Information [Line Items]
Revenues	4,158	5,222	8,536	10,579
Operating income (loss)	(12)	396	166	755
Capital expenditures	0	0	0	1
Capitalized software	0	0	0	0
Depreciation and amortization	1	2	3	4
Earnings (loss) before income taxes	(12)	396	166	755
Other
Segment Reporting Information [Line Items]
Revenues	565	697	1,223	1,281
Operating income (loss)	(3,505)	(2,843)	(6,737)	(5,662)
Capital expenditures	84	128	163	769
Capitalized software	0	0	0	0
Depreciation and amortization	93	83	184	153
Earnings (loss) before income taxes	$ (2,913)	$ (3,068)	$ (5,805)	$ (5,117)