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
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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Summary of Significant Accounting Policies - Concentration of Risk (Details)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenue benchmark \| Customer concentration risk \| Intel
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	15.00%	14.00%
Revenue benchmark \| Customer concentration risk \| Samsung Group
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%	11.00%	11.00%
Net accounts receivable \| Credit concentration risk \| Intel
Concentration Risk [Line Items]
Concentration risk, percentage	9.00%	9.00%
Net accounts receivable \| Credit concentration risk \| Samsung Group
Concentration Risk [Line Items]
Concentration risk, percentage	7.00%	7.00%