Income Taxes - Tax Effects of Temporary Differences That Give Rise to Significant Portions of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Deferred tax assets:
Accruals and expenses not deducted for tax purposes	$ 234	$ 473
IRS Section 174 costs	3,651	0
State net operating loss carryforwards	13	49
Fixed asset basis differences	516	823
Nonqualified stock options	2,676	1,740
Foreign net operating loss carryforwards	2,860	3,873
Right of use liability	117	251
Tax credit carryforwards	83	83
Total gross deferred tax assets	10,150	7,292
Less valuation allowance	(2,861)	(3,891)
Net deferred tax	7,289	3,401
Deferred tax liabilities:
Capitalized computer software development costs	(96)	(396)
Net gains/losses on trading securities	(2,160)	(1,993)
Goodwill and intangible assets basis differences	(1,705)	(1,399)
Right of use asset	(108)	(234)
Deferred agent commissions	(900)	(1,151)
Total gross deferred tax liabilities	(4,969)	(5,173)
Net deferred tax assets (liabilities)	$ 2,320
Net deferred tax assets (liabilities)		$ (1,772)