Detail of Selected Balance Sheet Accounts (Tables)

9 Months Ended

Jun. 30, 2012

Detail of Selected Balance Sheet Accounts [Abstract]

Activity in allowance for doubtful accounts receivable

	Three Months Ended June  30,						Nine Months Ended June  30,
	2012			2011			2012		2011
Balance at beginning of period	$	1,043		$	1,508		$	391	$	907
Increase (decrease) to bad debt expense		(127	)		(524	)		509		82
Deductions for uncollectible accounts written off, net of recoveries		175			(221	)		175		(225	)
Increase (decrease) due to foreign currency translation		5			(4	)		21		(5	)
Balance at end of period	$	1,096		$	759		$	1,096	$	759

Activity in product warranty accrual

	Three Months Ended June  30,						Nine Months Ended June  30,
	2012			2011			2012			2011
Balance at beginning of period	$	4,783		$	5,763		$	4,603		$	5,929
Increase (decrease) to warranty expense		752			(148	)		2,084			759
Deductions for warranty charges		(1,068	)		(728	)		(2,254	)		(1,961	)
Increase (decrease) due to foreign currency translation		(40	)		191			(6	)		351
Balance at end of period	$	4,427		$	5,078		$	4,427		$	5,078

Components of inventories

	June 30, 2012			September 30, 2011
Raw materials, parts and subassemblies	$	41,207		$	38,400
Work-in-progress		7,967			5,892
Provision for excess and obsolete inventory		(8,558	)		(7,652	)
Total inventories	$	40,616		$	36,640

Cost and Estimated Earnings on Uncompleted Contracts

	June 30, 2012			September 30, 2011
Costs incurred on uncompleted contracts	$	528,599		$	475,525
Estimated earnings		160,668			131,367
		689,267			606,892
Less: Billings to date		655,645			599,847
Net underbilled position	$	33,622		$	7,045
Included in the accompanying balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts — underbilled	$	87,036		$	51,568
Billings in excess of costs and estimated earnings on uncompleted contracts — overbilled		(53,414	)		(44,523	)
Net underbilled position	$	33,622		$	7,045