For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6351-108592

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13537-108611

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Credit Concentration (Details)	12 Months Ended
Credit Concentration (Details)	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Accounts Receivable [Member] \| Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage	14.40%	21.00%
Accounts Receivable [Member] \| Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage	21.90%	21.40%
Sales Revenue, Gross [Member] \| Customer A [Member]
Concentration Risk [Line Items]
Concentration risk percentage	26.50%	28.60%	35.70%
Sales Revenue, Gross [Member] \| Customer B [Member]
Concentration Risk [Line Items]
Concentration risk percentage	18.60%	20.60%	22.80%