For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Summary of business and significant accounting policies - Concentration of Risk and Significant Customers (Details) - Customer Concentration Risk	3 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020
Ford Motor Company \| Sales Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	45.00%	52.00%
Ford Motor Company \| Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	38.00%		39.00%
GM \| Sales Revenue
Concentration Risk [Line Items]
Concentration risk, percentage	45.00%	25.00%
GM \| Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	46.00%		44.00%
Grab \| Sales Revenue
Concentration Risk [Line Items]
Concentration risk, percentage		10.00%