Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Apr. 30, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets		$ 86	$ 113		$ 174	$ 232
Cash received from amended supply agreement						2,333
Other current assets		2,829			2,829		$ 3,916
Long term receivable		2,333			$ 2,333		$ 2,333
Deferred credit amortization period					4 years
Gains in other income		507	$ 879		$ 1,015	$ 1,386
General Electric Company
Finite Lived Intangible Assets [Line Items]
Cash received from amended supply agreement				$ 10,000
Additional amount paid on execution of agreement					$ 7,000
Acquired finite-lived intangible assets, period					3 years
Other current assets		$ 2,300			$ 2,300
Deferred credit								$ 8,100
General Electric Company | Subsequent Event
Finite Lived Intangible Assets [Line Items]
Cash received from amended supply agreement	$ 2,300
Supply Agreement
Finite Lived Intangible Assets [Line Items]
Useful life of intangible asset					15 years