Other Balance Sheet Information (Tables)

3 Months Ended

Dec. 31, 2016

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Accounts Receivable

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

	December 31, 2016			September 30, 2016
Accounts receivable	$	116,740		$	108,713
Less: allowance for doubtful accounts	(2,209		)	(2,241		)
Less: allowance for sales returns	(102		)	(100		)
Accounts receivable, net	$	114,429		$	106,372

Summary of Inventories

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

	December 31, 2016		September 30, 2016
Inventories:
Raw materials and purchased parts	$	59,775	$	60,979
Work-in-process	13,899		16,090
Finished goods	18,845		15,503
Total inventories	$	92,519	$	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 months ended December 31, 2016 and 2015 (in thousands):

Activity - Three Months Ended December 31, 2016
Balance at September 30, 2016		Accruals		Costs Incurred			Balance at December 31, 2016
$	6,324	$	2,507	$	(2,614	)	$	6,217

Activity - Three Months Ended December 31, 2015
Balance at September 30, 2015		Accruals		Costs Incurred			Balance at December 31, 2015
$	6,089	$	2,124	$	(2,446	)	$	5,767