Other Balance Sheet Information (Tables)

6 Months Ended

Mar. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Accounts Receivable

The following is a summary of accounts receivable at March 31, 2017 and September 30, 2016 (in thousands):

	March 31, 2017			September 30, 2016
Accounts receivable	$	117,070		$	108,713
Less: allowance for doubtful accounts	(1,742		)	(2,241		)
Less: allowance for sales returns	(157		)	(100		)
Accounts receivable, net	$	115,171		$	106,372

Summary of Inventories

The following is a summary of inventories at March 31, 2017 and September 30, 2016 (in thousands):

	March 31, 2017		September 30, 2016
Inventories:
Raw materials and purchased parts	$	65,394	$	60,979
Work-in-process	15,490		16,090
Finished goods	18,220		15,503
Total inventories	$	99,104	$	92,572

Product Warranty and Retrofit Activity on Gross Basis

The following is a summary of product warranty and retrofit activity on a gross basis for the three and six months ended March 31, 2017 and 2016 (in thousands):

Activity - Three Months Ended March 31, 2017
Balance at December 31, 2016		Accruals		Costs Incurred			Balance at March 31, 2017
$	6,217	$	2,709	$	(1,853	)	$	7,073

Activity - Three Months Ended March 31, 2016
Balance at December 31, 2015		Accruals		Costs Incurred			Balance at March 31, 2016
$	5,767	$	2,376	$	(2,408	)	$	5,735

Activity - Six Months Ended March 31, 2017
Balance at September 30, 2016		Accruals		Costs Incurred			Balance at March 31, 2017
$	6,324	$	5,216	$	(4,467	)	$	7,073

Activity - Six Months Ended March 31, 2016
Balance at September 30, 2015		Accruals		Costs Incurred			Balance at March 31, 2016
$	6,089	$	4,712	$	(5,066	)	$	5,735