Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Cash flows from operating activities:
Net earnings			$ 6,261	$ 2,726
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	$ 1,039	$ 1,514	2,170	3,194
Stock-based compensation expense	1,000	700	1,817	1,198
Net gain on investments			(1,193)	(803)
Deferred income taxes			(99)	(344)
Changes in operating assets and liabilities:
Purchases of trading securities			(174)	(285)
Proceeds from maturities and sales of trading securities			210	3,119
Accounts receivable, net			4,502	4,009
Prepaid expenses and other assets			(2,013)	322
Accounts payable and other liabilities			(2,595)	(3,344)
Deferred revenue			(1,174)	(3,021)
Net cash provided by operating activities			7,712	6,771
Cash flows from investing activities:
Capitalized computer software development costs			0	(371)
Purchases of property and equipment, net of disposals	(313)	(45)	(615)	(163)
Net cash used in investing activities			(615)	(534)
Cash flows from financing activities:
Proceeds from exercise of stock options			5,714	2,853
Dividends paid			(7,268)	(7,118)
Net cash used in financing activities			(1,554)	(4,265)
Net change in cash and cash equivalents			5,543	1,972
Cash and cash equivalents at beginning of period			88,658	79,814
Cash and cash equivalents at end of period	94,201	81,786	94,201	81,786
Supplemental disclosures of noncash operating, investing and financing activities:
Income taxes, net of refunds			176	205
Accrual of dividends payable	$ 3,676	$ 3,576	$ 3,676	$ 3,576