Other Balance Sheet Information (Tables)

3 Months Ended

Dec. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Accounts Receivable

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

	December 31,		September 30,
	2017		2017
Accounts receivable	$	140,490	$	122,868
Less allowance for doubtful accounts		(1,384)		(1,959)
Less allowance for sales returns		(59)		(81)
Accounts receivable, net	$	139,047	$	120,828

Summary of Inventories

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

	December 31,		September 30,
	2017		2017
Inventories
Raw materials and purchased parts	$	76,389	$	73,819
Work-in-process		11,729		10,548
Finished goods		26,915		22,028
Total inventories	$	115,033	$	106,395

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, 2017 and 2016 (in thousands):

Activity -Three Months Ended December 31, 2017
Balance						Balance
September 30,						December 31,
2017		Accruals		Costs Incurred		2017
$	8,054	$	2,336	$	(2,172)	$	8,218

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