Significant Accounting Policies - Additional Information (Detail) - USD ($)	9 Months Ended
Jan. 31, 2018	May 01, 2018
Significant Accounting Policies [Line Items]
Impact of Restatement on Opening Retained Earnings, Net of Tax		$ 35,425
Previously Reported [Member]
Significant Accounting Policies [Line Items]
Increase (Decrease) in Restricted Cash	$ 64,537

Amount after tax of cumulative effect of restatement on the opening retained earnings of the earliest year presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22644-107794

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant