Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended			9 Months Ended
		Jan. 31, 2021		Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Revenues:
Revenues		$ 27,683		$ 30,600	$ 82,842	$ 86,193
Cost of revenues:
Cost of revenues		12,422		13,158	38,523	38,943
Gross margin		15,261		17,442	44,319	47,250
Research and development		4,242		3,853	12,674	11,390
Sales and marketing		5,029		5,519	15,202	16,246
General and administrative		5,002		5,194	13,833	14,923
Amortization of acquisition-related intangibles		53		57	159	232
Total operating expenses		14,326		14,623	41,868	42,791
Operating income		935		2,819	2,451	4,459
Other income:
Interest income		90		360	313	1,234
Other, net		1,342		618	2,409	981
Earnings before income taxes		2,367		3,797	5,173	6,674
Income tax expense		56		511	136	477
Net earnings		$ 2,311	[1]	$ 3,286	$ 5,037	$ 6,197
Earnings per common share
Basic (in usd per share)	[2]	$ 0.07		$ 0.10	$ 0.16	$ 0.20
Diluted (in usd per share)	[2]	0.07		0.10	0.15	0.19
Cash dividends declared per common share (in usd per share)		$ 0.11		$ 0.11	$ 0.33	$ 0.33
Shares used in the calculation of earnings per common share
Basic (in shares)		32,628		31,955	32,485	31,611
Diluted (in shares)		33,293		32,668	33,107	32,260
Class B Common Shares
Earnings per common share
Basic (in usd per share)		$ 0.07		$ 0.10	$ 0.16	$ 0.20
Diluted (in usd per share)		$ 0.07		$ 0.10	$ 0.16	$ 0.20
Shares used in the calculation of earnings per common share
Basic (in shares)		1,822		1,822	1,822	1,822
Diluted (in shares)		1,822		1,822	1,822	1,822
Subscription Fees
Revenues:
Revenues		$ 7,486		$ 5,802	$ 20,815	$ 15,752
Cost of revenues:
Cost of revenues		3,062		1,976	8,767	6,711
License
Revenues:
Revenues		530		3,695	1,767	6,519
Cost of revenues:
Cost of revenues		288		1,582	1,516	3,969
Professional Services and Other
Revenues:
Revenues		9,495		10,308	29,551	31,271
Cost of revenues:
Cost of revenues		7,178		7,764	22,632	22,712
Maintenance
Revenues:
Revenues		10,172		10,795	30,709	32,651
Cost of revenues:
Cost of revenues		$ 1,894		$ 1,836	$ 5,608	$ 5,551

[1] Amounts adjusted for rounding

[2] Basic per share amounts are the same for Class A and Class B shares. Diluted per share amounts for Class A shares are shown above. Diluted earnings per share for Class B shares under the two-class method are $0.07 and $0.10 for the three months ended January 31, 2021 and 2020, respectively, and $0.16 and $0.20 for the nine months ended January 31, 2021 and 2020, respectively. See Note E to the Condensed Consolidated Financial Statements.