Goodwill and Intangible Assets - Narrative (Details) - USD ($)			1 Months Ended	12 Months Ended
	Dec. 30, 2013	Aug. 07, 2006	Apr. 30, 2017	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				205,000	355,000	352,000
Cash received from amended supply agreement	$ 10,000,000		$ 2,300,000	$ 0	2,333,000	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				$ 747,000	2,029,000	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				$ 510,000	$ 716,000
Supply Agreement
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible asset		15 years