Segment Data and Related Information (Narrative) (Details)	12 Months Ended
	Sep. 30, 2020 product customer segment	Sep. 30, 2019 customer	Sep. 30, 2018 customer
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of reporting segments | segment	2
Concentration risk, customers | customer	3	3	2
Percentage of long-lived assets located in the United States	97.00%	85.00%
Aerospace and Defense Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Product Lines	2
Broadband segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Product Lines	3
Customer Concentration Risk | Sales Revenue, Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Concentration risk percentage	57.00%	55.00%	60.00%