Share Capital - Summary of Changes In Options (Detail)	12 Months Ended
Apr. 30, 2019 CAD ($) Option	Apr. 30, 2018 CAD ($) Option	Apr. 30, 2017 CAD ($)
Disclosure of defined benefit plans [abstract]
Beginning balance, shares \| Option	948,750	1,348,750
Forfeited/expired , shares \| Option	(948,750)	(400,000)
Ending balance, shares \| Option	0	948,750
Weighted average exercise price, Forfeited/expired \| $		$ 0.94
Weighted average exercise price,expired \| $	$ 0.88
Weighted average exercise price, Outstanding and Exercisable \| $	$ 0	$ 0.88	$ 0.90

No definition available.

Name:	ifrs-full_DisclosureOfDefinedBenefitPlansAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of share options outstanding in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_d&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_i&doctype=Standard
-URIDate 2018-03-16

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph b
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vi&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_NumberOfOutstandingShareOptions
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of share options forfeited in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_iii&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_NumberOfShareOptionsForfeitedInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average exercise price of share options expired in a share-based payment arrangement. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph b
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_v&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_WeightedAverageExercisePriceOfShareOptionsExpiredInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average exercise price of share options forfeited in a share-based payment arrangement. [Refer: Weighted average [member]]

+ References

+ Details

Name:	ifrs-full_WeightedAverageExercisePriceOfShareOptionsForfeitedInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average exercise price of share options outstanding in a share-based payment arrangement. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_i&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2018-01-01
-Paragraph 45
-Subparagraph b
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vi&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant