Commitments and Contingencies (Narrative) (Details)			1 Months Ended			12 Months Ended
	Jan. 06, 2017 USD ($)	Sep. 23, 2014 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2012 USD ($)	Sep. 30, 2018 USD ($) building	Sep. 30, 2017 USD ($) building	Sep. 30, 2016 USD ($)	May 31, 2018 USD ($)	May 31, 2016
Loss Contingencies [Line Items]
Estimated future minimum lease payments, 2019						$ 800,000
Estimated future minimum lease payments, 2020						800,000
Estimated future minimum lease payments, 2021						600,000
Estimated future minimum lease payments, 2022						600,000
Estimated future minimum lease payments, 2023						700,000
Rent expense						$ 1,200,000	$ 1,400,000	$ 1,400,000
Fair value assumptions, credit adjusted risk-free rate, range minimal amount						1.20%
Fair value assumptions, credit adjusted risk-free rate, range maximum amount						4.20%
Accretion expense						$ 66,000	100,000	100,000
Asset retirement obligation						1,809,000	1,638,000
Asset retirement obligation, increase (decrease)						$ 100,000	(45,000)	(300,000)
Payments to terminate lease agreement								200,000
Amount of indemnification under Master Purchase Agreement					$ 3,400,000.0
Period of indemnification under Master Purchase Agreement					2 years
Sumitomo Electric Industries, LTD
Loss Contingencies [Line Items]
Damages sought in arbitration		$ 47,500,000
Gain on settlement								3,400,000
Settled Litigation | Sumitomo Electric Industries, LTD
Loss Contingencies [Line Items]
Amount entitled to collect, held in escrow			$ 1,900,000
Amount recovered in fees and costs from other party								2,600,000
Settled Litigation | Mirasol Class Action
Loss Contingencies [Line Items]
Litigation settlement, awarded to other party	$ 300,000
Settlement agreement									$ 300,000
Provision accrual							$ 200,000
Settled Litigation | Mirasol Wrongful Termination
Loss Contingencies [Line Items]
Litigation settlement, awarded to other party	$ 50,000
Buildings | Property Subject to Operating Lease
Loss Contingencies [Line Items]
Number of leased buildings | building						6
Leases retroactively effective | building							4
Lease term (in years)						3 years
Operating lease, term extension, option to extend (in years)						3 years
Property in Alhambra, California
Loss Contingencies [Line Items]
Asset retirement obligation						$ 1,800,000	$ 1,600,000
Property in Beijing, China
Loss Contingencies [Line Items]
Lease term (in years)										5 years
Asset retirement obligation						$ 100,000	$ 100,000
Discontinued Operations, Disposed of by Sale
Loss Contingencies [Line Items]
Payments to terminate lease agreement				$ 200,000				200,000
Discontinued Operations, Disposed of by Sale | Sumitomo Electric Industries, LTD
Loss Contingencies [Line Items]
Gain on settlement								3,800,000
Write off of loss accrual								$ 400,000