Income and Other Taxes (Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Federal net operating loss carryforwards	$ 99,298	$ 91,639
Foreign net operating loss carryforwards	1,271	1,301
Income tax credit carryforwards	2,671	2,671
Inventory reserves	3,535	2,065
Accounts receivable reserves	50	123
Accrued warranty reserve	153	144
State net operating loss carryforwards	6,174	4,624
Stock compensation	704	728
Deferred compensation	404	200
Fixed assets and intangibles	(2,693)	(33)
Other	2,255	838
Total deferred tax assets	113,822	104,300
Valuation allowance	(113,891)	(104,300)
Net deferred tax liabilities	$ (69)	$ 0