Recent Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016	Jun. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit	$ (565,177)	$ (571,207)
Operating lease obligations	$ 1,100
Average discounted rate	4.00%
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-18 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash	$ 400		$ 1,200
Minimum [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on balance sheet	1,200
Maximum [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on balance sheet	$ 2,500