Leases (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Lessee Lease Description [Line Items]
Lease initial term		12 months
Non-cash impairment charge	$ 37,902
Total rental payments			$ 7,578	$ 8,348
Revenue included embedded operating leases		$ 6,823
Disposal Groups [Member]
Lessee Lease Description [Line Items]
Non-cash impairment charge		$ 639