Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Cash flows from operating activities:
Net earnings			$ 6,197	$ 4,929
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	$ 1,882	$ 1,960	6,310	5,671
Stock-based compensation expense	600	500	1,510	1,308
Net (gain)/loss on investments			(1,036)	393
Deferred income taxes			(192)	(166)
Changes in operating assets and liabilities:
Purchases of trading securities			(21,934)	(7,427)
Proceeds from maturities and sales of trading securities			22,687	12,944
Accounts receivable, net			(3,344)	(831)
Prepaid expenses and other assets			(1,279)	724
Accounts payable and other liabilities			3,058	(4,031)
Deferred revenue			1,135	94
Net cash provided by operating activities			13,112	13,608
Cash flows from investing activities:
Capitalized computer software development costs			(2,697)	(4,162)
Purchases of property and equipment, net of disposals	(101)	(120)	(339)	(1,014)
Net cash used in investing activities			(3,036)	(5,176)
Cash flows from financing activities:
Proceeds from exercise of stock options			7,837	4,004
Dividends paid			(10,392)	(10,172)
Net cash used in financing activities			(2,555)	(6,168)
Net change in cash and cash equivalents			7,521	2,264
Cash and cash equivalents at beginning of period			61,288	52,794
Cash and cash equivalents at end of period	68,809	55,058	68,809	55,058
Cash paid during the period for:
Income taxes, net of refunds			504	505
Supplemental disclosures of noncash operating, investing and financing activities:
Accrual of dividends payable	$ 3,523	$ 3,416	$ 3,523	$ 3,416