Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013	Jun. 30, 2015	Sep. 30, 2016
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 88	$ 88
Other current assets	$ 2,608				$ 2,457
Deferred credit amortization period	4 years
Gains in other income	$ 507	507
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
Deferred credit			$ 8,100
General Electric Company | Other Income
Finite Lived Intangible Assets [Line Items]
Gains in other income	$ 500	$ 500
Supply Agreement
Finite Lived Intangible Assets [Line Items]
Useful life of intangible asset	15 years