Segment Data and Related Information (Narrative) (Details)	3 Months Ended
	Dec. 31, 2020 customer segment	Dec. 31, 2019 customer	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of reporting segments | segment	2
Concentration risk percentage	100.00%	100.00%
Percentage of long-lived assets located in the United States	98.00%		97.00%
Customer Concentration Risk
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Concentration risk, customers | customer	3	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	70.00%	50.00%