Earnings Per Share (Tables)

9 Months Ended

Jun. 30, 2012

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

	Three Months Ended June 30,					Nine Months Ended June 30,
	2012			2011		2012			2011
	(in thousands, except per share amounts)					(in thousands, except per share amounts)
Basic Earnings (Loss) Per Share Computation
Net income (loss) attributable to Amtech Systems, Inc.	$	(2,965	)	$	7,298	$	(8,920	)	$	19,807
Weighted Average Shares Outstanding:
Common stock	9,479			9,576		9,468			9,446
Basic earnings (loss) per share attributable to Amtech shareholders	$	(0.31	)	$	0.76	$	(0.94	)	$	2.10
Diluted Earnings (Loss) Per Share Computation
Net income (loss) attributable to Amtech Systems, Inc.	$	(2,965	)	$	7,298	$	(8,920	)	$	19,807
Weighted Average Shares Outstanding:
Common stock	9,479			9,576		9,468			9,446
Common stock equivalents (1)	—			276		—			308
Diluted shares	9,479			9,852		9,468			9,754
Diluted earnings (loss) per share attributable to Amtech shareholders	$	(0.31	)	$	0.74	$	(0.94	)	$	2.03

(1) The number of common stock equivalents is calculated using the treasury stock method and the average market price during the period.