Schedule of Derivative Instruments (Details) - USD ($)	Jul. 31, 2019	Apr. 30, 2019
Foreign currency option contracts	$ 1,400,000	$ 1,500,000

The amount of foreign currency that the entity has contractually agreed, or for which it has the option, to buy or sell with respect to the contract being described.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

Name:	invest_InvestmentForeignCurrencyContractForeignCurrencyAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant