Goodwill and Intangible Assets - Narrative (Details) - USD ($)			1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 30, 2013	Aug. 07, 2006	Apr. 30, 2017	Dec. 31, 2012	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Goodwill					$ 1,000,000
Impairment of goodwill					0	$ 0	$ 0
Amortization of intangible assets					177,000	205,000	355,000
Cash received from amended supply agreement	$ 10,000,000		$ 2,300,000		0	0	2,333,000
Additional amount paid on execution of agreement	$ 7,000,000
Acquired finite-lived intangible assets, period	3 years
Deferred credit									$ 8,100,000
Deferred credit amortization period				4 years
Gains in other income					0	747,000	2,029,000
Other Income
Finite-Lived Intangible Assets [Line Items]
Gains in other income						500,000	$ 2,000,000	$ 2,000,000
Purchased Technology
Finite-Lived Intangible Assets [Line Items]
Purchased technology					$ 334,000	$ 510,000
Supply Agreement
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible asset		15 years