Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Revenue, net of returns and allowances	$ 104,883	$ 56,501	$ 34,798
Cost of sales	77,737	44,581	26,833
Write-down of inventory	138	294	3,652
Gross profit	27,008	11,626	4,313
Selling, general and administrative	33,028	18,424	16,830
Research, development and engineering	6,918	6,291	6,594
Restructuring charges	583	0	883
Operating loss	(13,521)	(13,089)	(19,994)
Gain on deconsolidation of Kingstone	8,814	0	0
Interest and other (expense) income, net	(100)	40	147
Loss before income taxes	(4,807)	(13,049)	(19,847)
Income tax provision	1,910	1,240	1,860
Net loss	(6,717)	(14,289)	(21,707)
Add: net (income) loss attributable to noncontrolling interest	(1,054)	1,242	1,638
Net loss attributable to Amtech Systems, Inc.	$ (7,771)	$ (13,047)	$ (20,069)
Income (Loss) Per Share:
Basic income (loss) per share attributable to Amtech shareholders (dollars per share)	$ (0.65)	$ (1.34)	$ (2.11)
Weighted average shares outstanding (in shares)	12,022	9,732	9,529
Diluted income (loss) per share attributable to Amtech shareholders (dollars per share)	$ (0.65)	$ (1.34)	$ (2.11)
Weighted average shares outstanding (in shares)	12,022	9,732	9,529