Industry Segments - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024
Segment Reporting Information [Line Items]
Revenue	$ 25,007	$ 25,536	$ 76,485	$ 77,127
Operating income (loss)	(3,513)	815	(633)	3,436
Capital expenditures	103	68	383	589
Depreciation and amortization	1,155	1,634	3,509	3,641
Earnings (loss) before income taxes	(2,733)	5,232	2,461	9,162
Supply Chain Management
Segment Reporting Information [Line Items]
Revenue	24,192	24,741	74,069	74,535
Operating income (loss)	4,768	6,014	17,502	17,778
Capital expenditures	14	21	41	434
Depreciation and amortization	987	1,462	3,006	3,115
Earnings (loss) before income taxes	5,109	7,705	18,948	19,735
Other
Segment Reporting Information [Line Items]
Revenue	815	795	2,416	2,592
Operating income (loss)	(8,281)	(5,199)	(18,135)	(14,342)
Capital expenditures	89	47	342	155
Depreciation and amortization	168	172	503	526
Earnings (loss) before income taxes	$ (7,842)	$ (2,473)	$ (16,487)	$ (10,573)