Segment Information - Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Segment Reporting Information [Line Items]
Revenues from external customers	$ 26,098	$ 31,185	$ 58,101	$ 57,868
Earnings (loss) before income taxes	1,152	1,221	3,576	2,280
Domestic Operations [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	22,061	25,683	49,134	48,312
Intersegment revenues	532	688	1,936	1,418
Earnings (loss) before income taxes	1,382	1,438	4,564	3,322
International Operations [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	4,037	5,502	8,967	9,556
Intersegment revenues	762	918	1,248	1,422
Earnings (loss) before income taxes	584	784	1,141	1,030
Corporate [Member]
Segment Reporting Information [Line Items]
Intersegment revenues	(1,294)	(1,606)	(3,184)	(2,840)
Earnings (loss) before income taxes	$ (814)	$ (1,001)	$ (2,129)	$ (2,072)

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

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