Income and other Taxes (Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Federal net operating loss carryforwards	$ 144,455	$ 147,449
Foreign net operating loss carryforwards	587	51
Income tax credit carryforwards	3,211	3,062
Inventory reserves	2,037	2,614
Accounts receivable reserves	8	14
Accrued warranty reserve	249	328
State net operating loss carryforwards	4,525	7,009
Stock compensation	2,367	3,334
Deferred compensation	349	896
Fixed assets and intangibles	136	124
Other	927	728
Total deferred tax assets	158,851	165,609
Valuation allowance	(158,851)	(165,609)
Net deferred tax assets	$ 0	$ 0