Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands			3 Months Ended				9 Months Ended
		Nov. 15, 2018	Jan. 31, 2019		Jan. 31, 2018		Jan. 31, 2019		Jan. 31, 2018
Revenues:
Revenues			$ 27,003		$ 30,117		$ 82,435		$ 83,340
Cost of revenues:
Cost of revenues			12,964		13,071		39,977		37,063
Gross margin			14,039		17,046		42,458		46,277
Research and development			2,811		3,099		9,818		8,250
Sales and marketing			4,699		5,385		15,183		15,055
General and administrative			4,302		4,263		12,903		11,418
Amortization of acquisition-related intangibles			97		95		291		486
Total operating expenses			11,909		12,842		38,195		35,209
Operating income			2,130		4,204		4,263		11,068
Other (expense)/income:
Interest income			523		403		1,551		1,120
Other, net			4		1,171		(461)		1,729
Income tax expense			2,657		5,778		5,353		13,917
Income tax expense			356		198		424		3,132
Net earnings			$ 2,301		$ 5,580		$ 4,929		$ 10,785
Earnings per common share (a):
Basic earnings per common share (in usd per share)	[1]		$ 0.07		$ 0.18		$ 0.16		$ 0.36
Diluted earnings per common share (in usd per share)	[1]		0.07		0.18		0.16		0.36
Cash dividends declared per common share (in usd per share)		$ 0.11	$ 0.11	[1]	$ 0.11	[1]	$ 0.33	[1]	$ 0.33	[1]
Shares used in the calculation of earnings per common share
Basic shares used in calculation of earnings per common share (in shares)			31,010		30,244		30,887		29,940
Diluted shares used in calculation of earnings per common share (in shares)			31,183		30,701		31,351		30,299
License
Revenues:
Revenues			$ 1,718		$ 5,955		$ 5,432		$ 12,420
Cost of revenues:
Cost of revenues			1,831		1,727		5,305		4,692
Subscription Fees
Revenues:
Revenues			3,687		2,584		10,196		6,244
Cost of revenues:
Cost of revenues			1,389		1,028		3,746		2,779
Professional Services and Other
Revenues:
Revenues			10,176		10,342		32,240		31,773
Cost of revenues:
Cost of revenues			7,714		7,912		24,484		22,673
Maintenance
Revenues:
Revenues			11,422		11,236		34,567		32,903
Cost of revenues:
Cost of revenues			$ 2,030		$ 2,404		$ 6,442		$ 6,919

[1] (a)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 $0.18 for the three months ended January 31, 2019 and 2018, and $0.16 and $0.36 for the nine months ended January 31, 2019 and 2018, respectively. See Note D to the Condensed Consolidated Financial Statements.