Other Balance Sheet Information (Tables)

3 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Accounts Receivable

The following is a summary of accounts receivable at December 31, 2018 and September 30, 2018 (in thousands):

	December 31,		September 30,
	2018		2018
Accounts receivable	$	165,670	$	126,350
Less allowance for doubtful accounts		(1,114)		(1,113)
Less allowance for sales returns		(40)		(45)
Accounts receivable, net	$	164,516	$	125,192

Summary of Inventories

The following is a summary of inventories at December 31, 2018 and September 30, 2018 (in thousands):

	December 31,		September 30,
	2018		2018
Inventories
Raw materials and purchased parts	$	67,428	$	57,527
Work-in-process		13,799		19,547
Finished goods		28,843		19,912
Total inventories	$	110,070	$	96,986

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, 2018 and 2017 (in thousands):

Activity -Three Months Ended December 31, 2018
Balance						Balance
September 30,						December 31,
2018		Accruals		Costs Incurred		2018
$	6,340	$	2,355	$	(1,844)	$	6,851

Activity -Three Months Ended December 31, 2017
Balance						Balance
September 30,						December 31,
2017		Accruals		Costs Incurred		2017
$	5,479	$	1,408	$	(1,313)	$	5,574