Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024	Apr. 30, 2024
Accounting Policies [Abstract]
Working capital deficit	$ 173,000		$ 173,000
Accumulated deficit	78,057,000		78,057,000		$ 84,593,000
Unrecognized tax benefits	181,000		181,000		$ 181,000
Income tax penalties and interest expense	0	$ 0	0	$ 0
Unrecognized tax benefits anticipated during the next 12 months	0		0
Provision for income taxes	$ 23,000	$ 11,000	$ 54,000	$ 49,000