Major Customers and Sales by Country - Schedule of Revenues by Geographic Region (Details) - Net Revenues - Geographic Concentration Risk	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Revenue, Major Customer [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%
United States
Revenue, Major Customer [Line Items]
Concentration risk, percentage	28.00%	35.00%	21.00%
Other Americas
Revenue, Major Customer [Line Items]
Concentration risk, percentage	7.00%	6.00%	3.00%
Total Americas
Revenue, Major Customer [Line Items]
Concentration risk, percentage	35.00%	41.00%	24.00%
China
Revenue, Major Customer [Line Items]
Concentration risk, percentage	25.00%	18.00%	30.00%
Malaysia
Revenue, Major Customer [Line Items]
Concentration risk, percentage	5.00%	5.00%	8.00%
Taiwan
Revenue, Major Customer [Line Items]
Concentration risk, percentage	15.00%	10.00%	9.00%
Other Asia
Revenue, Major Customer [Line Items]
Concentration risk, percentage	7.00%	8.00%	5.00%
Total Asia
Revenue, Major Customer [Line Items]
Concentration risk, percentage	52.00%	41.00%	52.00%
Germany
Revenue, Major Customer [Line Items]
Concentration risk, percentage	3.00%	8.00%	10.00%
Other Europe
Revenue, Major Customer [Line Items]
Concentration risk, percentage	10.00%	10.00%	14.00%
Total Europe
Revenue, Major Customer [Line Items]
Concentration risk, percentage	13.00%	18.00%	24.00%