Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Revenue, net of returns and allowances	$ 56,501	$ 34,798	$ 81,539
Cost of sales	44,581	26,833	59,511
Write-down of inventory	294	3,652	10,380
Losses on inventory purchase commitments	0	0	2,455
Gross profit	11,626	4,313	9,193
Selling, general and administrative	18,424	16,830	23,055
Research and development	6,291	6,594	13,694
Impairment and restructuring charges	0	883	5,428
Operating loss	(13,089)	(19,994)	(32,984)
Interest and other income, net	40	147	66
Loss before income taxes	(13,049)	(19,847)	(32,918)
Income tax provision (benefit)	1,240	1,860	(5,320)
Net loss	(14,289)	(21,707)	(27,598)
Add: net loss attributable to noncontrolling interest	1,242	1,638	4,567
Net loss attributable to Amtech Systems, Inc.	$ (13,047)	$ (20,069)	$ (23,031)
Income (Loss) Per Share:
Basic income (loss) per share attributable to Amtech shareholders (dollars per share)	$ (1.34)	$ (2.11)	$ (2.43)
Weighted average shares outstanding (in shares)	9,732	9,529	9,471
Diluted income (loss) per share attributable to Amtech shareholders (dollars per share)	$ (1.34)	$ (2.11)	$ (2.43)
Weighted average shares outstanding (in shares)	9,732	9,529	9,471