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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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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
-Name Accounting Standards Codification
-Topic 275
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-Section 50
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-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	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Ford Motor Company \| Revenue
Concentration Risk [Line Items]
Concentration risk	55.00%	67.00%	71.00%
Ford Motor Company \| Accounts receivable
Concentration Risk [Line Items]
Concentration risk	33.00%	56.00%
General Motors Holdings \| Revenue
Concentration Risk [Line Items]
Concentration risk	18.00%
General Motors Holdings \| Accounts receivable
Concentration Risk [Line Items]
Concentration risk	15.00%	10.00%
Xevo Inc \| Accounts receivable
Concentration Risk [Line Items]
Concentration risk	29.00%