Commitments and Contingencies (Narrative) (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 06, 2017 USD ($)	Mar. 31, 2018 USD ($) building	Mar. 31, 2017 USD ($)	Mar. 31, 2018 USD ($) building	Mar. 31, 2017 USD ($)	Sep. 30, 2017 USD ($) building
Loss Contingencies [Line Items]
Rent expense		$ 300	$ 400	$ 600	$ 700
Fair value assumptions, credit adjusted risk-free rate, range minimal amount		1.20%		1.20%
Fair value assumptions, credit adjusted risk-free rate, range maximum amount		4.20%		4.20%
Accretion expense		$ 16	$ 17	$ 33	34
Settled Litigation [Member] | Mirasol Class Action [Member]
Loss Contingencies [Line Items]
Litigation settlement, awarded to other party	$ 300
Settlement agreement		$ 300		$ 300
Provision accrual					$ 200
Settled Litigation [Member] | Mirasol Wrongful Termination [Member]
Loss Contingencies [Line Items]
Litigation settlement, awarded to other party	$ 50
Buildings [Member] | Property Subject to Operating Lease [Member]
Loss Contingencies [Line Items]
Number of leased buildings | building		6		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 [Member]
Loss Contingencies [Line Items]
Asset retirement obligation		$ 1,700		$ 1,700		$ 1,600