Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets		$ 88	$ 118
Cash received from amended supply agreement	$ 2,300			$ 10,000
Other current assets		4,244			$ 3,916
Long term receivable		$ 2,333			$ 2,333
Deferred credit amortization period		4 years
Gains in other income		$ 507	$ 507
General Electric Company
Finite Lived Intangible Assets [Line Items]
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
Supply Agreement
Finite Lived Intangible Assets [Line Items]
Useful life of intangible asset		15 years