Other Balance Sheet Information (Tables)

6 Months Ended

Mar. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Accounts Receivable

The following is a summary of accounts receivable at March 31, 2019 and September 30, 2018 (in thousands):

	March 31,		September 30,
	2019		2018
Accounts receivable	$	166,247	$	126,350
Less allowance for doubtful accounts		(2,548)		(1,113)
Less allowance for sales returns		(46)		(45)
Accounts receivable, net	$	163,653	$	125,192

Summary of Inventories

The following is a summary of inventories at March 31, 2019 and September 30, 2018 (in thousands):

	March 31,		September 30,
	2019		2018
Inventories
Raw materials and purchased parts	$	68,534	$	57,527
Work-in-process		15,607		19,547
Finished goods		24,371		19,912
Total inventories	$	108,512	$	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 and six months ended March 31, 2019 and 2018 (in thousands):

Activity -Three Months Ended March 31, 2019
Balance						Balance
December 31,						March 31,
2018		Accruals		Costs Incurred		2019
$	6,851	$	1,807	$	(1,456)	$	7,202

Activity -Three Months Ended March 31, 2018
Balance						Balance
December 31,						March 31,
2017		Accruals		Costs Incurred		2018
$	5,574	$	1,375	$	(1,315)	$	5,634

Activity -Six Months Ended March 31, 2019
Balance						Balance
September 30,						March 31,
2018		Accruals		Costs Incurred		2019
$	6,340	$	4,161	$	(3,299)	$	7,202

Activity -Six Months Ended March 31, 2018
Balance						Balance
September 30,						March 31,
2017		Accruals		Costs Incurred		2018
$	5,479	$	2,784	$	(2,629)	$	5,634