Summary of significant accounting policies.

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- Definition

Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

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Amount of lessee's right to use underlying asset under operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 10B
-URI http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318

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-SubTopic 10
-Section 50
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Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
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Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018	May 01, 2019
Summary of Significant Accounting Policies [Line Items]
Uncertain tax positions	$ 0	$ 0	$ 0
Interest or penalties charges recognized	0	$ 0	$ 0
Operating lease assets	1,612,000
Operating lease liabilities	$ 1,645,000
Topic 842 [Member]
Summary of Significant Accounting Policies [Line Items]
Operating lease assets				$ 1,900,000
Operating lease liabilities				$ 1,900,000