Consolidated Statements Of Stockholders' Equity And Comprehensive Income (Loss) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]	Total Amtech Systems Inc. Stockholders' Equity [Member]	Noncontrolling Interest [Member]
Beginning balance at Sep. 30, 2008	$ 74,533	$ 91	$ 70,135	$ 67	$ 4,240	$ 74,533
Beginning balance, shares at Sep. 30, 2008		9,096,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,589)				(1,589)	(1,589)
Translation adjustment	594			594		594
Comprehensive income (loss)	(995)					(995)
Share repurchase, shares		(144,000)
Share repurchase	(447)	(1)	(446)			(447)
Stock compensation expense	711		711			711
Restricted shares released		8,000
Stock options exercised, shares		2,000
Stock options exercised	3		3			3
Ending balance at Sep. 30, 2009	73,805	90	70,403	661	2,651	73,805
Ending balance, shares at Sep. 30, 2009		8,962,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	9,563				9,563	9,563
Translation adjustment	(1,643)			(1,643)		(1,643)
Comprehensive income (loss)	7,920					7,920
Tax benefit of stock options	202		202			202
Stock compensation expense	987		987			987
Restricted shares released		34,000
Stock options exercised, shares		214,000
Stock options exercised	1,329	2	1,327			1,329
Ending balance at Sep. 30, 2010	84,243	92	72,919	(982)	12,214	84,243
Ending balance, shares at Sep. 30, 2010	9,209,213	9,210,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	22,119				22,882	22,882	(763)
Translation adjustment	(1,136)			(1,096)		(1,096)	(40)
Comprehensive income (loss)	20,983					21,786	(803)
Deferred tax asset recorded due to legal reorganization	4,025		4,025			4,025
Acquired interest in Kingstone, shares		153,000
Acquired interest in Kingstone	10,650	2	3,833			3,835	6,815
Share repurchase, shares		(153,000)
Share repurchase	(1,225)	(2)	(1,223)			(1,225)
Tax benefit of stock options	855		855			855
Stock compensation expense	1,470		1,470			1,470
Restricted shares released		43,000
Stock options exercised, shares		178,000
Stock options exercised	1,330	2	1,328			1,330
Ending balance at Sep. 30, 2011	$ 122,331	$ 94	$ 83,207	$ (2,078)	$ 35,096	$ 116,319	$ 6,012
Ending balance, shares at Sep. 30, 2011	9,431,393	9,431,000