Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended								12 Months Ended
		Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Revenues:
Total revenues		$ 26,271	$ 27,003	$ 28,033	$ 27,399	$ 29,363	$ 30,117	$ 26,337	$ 26,886	$ 108,706	$ 112,703	$ 106,286
Cost of revenues:
Cost of revenues										51,966	50,000	51,084
Gross margin		14,282	14,039	14,667	13,752	16,426	17,046	14,006	15,225	56,740	62,703	55,202
Research and development										13,078	11,877	11,889
Sales and marketing										20,992	20,658	20,287
General and administrative										17,006	16,057	14,219
Amortization of acquisition-related intangibles										388	580	1,041
Total operating expenses										51,464	49,172	47,436
Operating income		1,013	2,130	1,526	607	2,463	4,204	3,242	3,622	5,276	13,531	7,766
Other income:
Interest income										2,092	1,575	1,257
Other, net										273	609	12,592
Earnings before income taxes										7,641	15,715	21,615
Income tax expense										838	3,662	6,994
Net earnings		$ 1,874	$ 2,301	$ 1,243	$ 1,385	$ 1,268	$ 5,580	$ 2,480	$ 2,725	$ 6,803	$ 12,053	$ 14,621
Earnings per common share
Basic (in usd per share)	[1]									$ 0.22	$ 0.40	$ 0.50
Diluted (in usd per share)		$ 0.06	$ 0.07	$ 0.04	$ 0.04	$ 0.04	$ 0.18	$ 0.08	$ 0.09	$ 0.22	$ 0.40	$ 0.49
Shares used in the calculation of earnings per common share:
Basic (in shares)										30,950	30,080	29,232
Diluted (in shares)										31,378	30,472	29,567
License
Revenues:
Total revenues										$ 7,126	$ 15,344	$ 15,584
Cost of revenues:
Cost of revenues										6,430	6,261	6,713
Subscriptions fees
Revenues:
Total revenues										14,026	8,855	4,381
Cost of revenues:
Cost of revenues										5,759	3,817	3,290
Professional services and other
Revenues:
Total revenues										42,154	44,663	43,932
Cost of revenues:
Cost of revenues										31,421	30,596	31,374
Maintenance
Revenues:
Total revenues										45,400	43,841	42,389
Cost of revenues:
Cost of revenues										$ 8,356	$ 9,326	$ 9,707
Class A Common Shares
Earnings per common share
Basic (in usd per share)										$ 0.22	$ 0.40	$ 0.50
Diluted (in usd per share)	[1]									$ 0.22	$ 0.40	$ 0.49
Shares used in the calculation of earnings per common share:
Basic (in shares)										29,106	27,805	26,793
Diluted (in shares)										31,379	30,472	29,567
Class B Common Shares
Earnings per common share
Basic (in usd per share)										$ 0.22	$ 0.39	$ 0.50
Diluted (in usd per share)										$ 0.22	$ 0.39	$ 0.49
Shares used in the calculation of earnings per common share:
Basic (in shares)										1,844	2,275	2,439
Diluted (in shares)										1,844	2,275	2,439

[1] Diluted per share amounts for Class A shares are shown above. Diluted per share for Class B shares under the two-class method are $0.22, $0.39 and $0.49 for the years ended April 30, 2019, 2018 and 2017, respectively. See Note 1 to the Consolidated Financial Statements.