Segmented Information and Other Additional Disclosures (Narrative) (Details) - USD ($)	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Disclosure Of Operating Segments Abstract
Information about major customers	During the year ended March 31, 2020, the Company was economically dependent on four (2019 - one, 2018 - two) customers who accounted for more than 10% of revenue from continuing operations
Percentage of revenue	86.00%	80.00%	100.00%
Vehicle sales revenue from government grants	$ 4,197,850	$ 622,420
Wages and salaries	$ 3,262,331	$ 1,909,196	$ 1,271,673

Represents the vehicle sales revenue from government grants.

No definition available.

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Namespace Prefix:	gpvrf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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- Definition

Information about the entity's major customers and the extent of the entity's reliance on them.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_34&doctype=Standard
-URIDate 2019-03-27

+ Details

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Namespace Prefix:	ifrs-full_
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Balance Type:	na
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- Definition

The percentage of the entity's revenue. [Refer: Revenue]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 8
-IssueDate 2019-01-01
-Paragraph 34
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2019-en-r&anchor=para_34&doctype=Standard
-URIDate 2019-03-27

+ Details

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- Definition

A class of employee benefits expense that represents wages and salaries. [Refer: Employee benefits expense]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2019-01-01
-Paragraph 9
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2019-en-r&anchor=para_9&doctype=Standard
-URIDate 2019-03-27

+ Details

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Balance Type:	debit
Period Type:	duration