Certain Balance Sheet Components

9 Months Ended

Sep. 30, 2021

Balance Sheet Related Disclosures [Abstract]

Certain Balance Sheet Components

Certain Balance Sheet Components

A summary of accounts receivable from contracts with customers is as follows:

Accounts receivable, net
In thousands	September 30, 2021		December 31, 2020
Trade receivables (net of allowance of $2,798 and $1,312)	$	274,385	$	318,269
Unbilled receivables	46,609		51,559
Total accounts receivable, net	$	320,994	$	369,828

Allowance for credit losses account activity	Three Months Ended September 30,				Nine Months Ended September 30,
In thousands	2021		2020		2021		2020
Beginning balance	$	1,107	$	2,102	$	1,312	$	3,064
Provision for (release of) doubtful accounts, net	2,164		(21)		2,122		318
Accounts written-off	(440)		(278)		(582)		(1,489)
Effect of change in exchange rates	(33)		43		(54)		(47)
Ending balance	$	2,798	$	1,846	$	2,798	$	1,846

Inventories
In thousands	September 30, 2021		December 31, 2020
Raw materials	$	117,549	$	114,058
Work in process	8,539		8,094
Finished goods	49,344		60,225
Total inventories	$	175,432	$	182,377

Property, plant, and equipment, net
In thousands	September 30, 2021		December 31, 2020
Machinery and equipment	$	333,584	$	334,050
Computers and software	117,067		115,776
Buildings, furniture, and improvements	146,052		155,676
Land	11,976		14,303
Construction in progress, including purchased equipment	40,082		31,425
Total cost	648,761		651,230
Accumulated depreciation	(459,013)		(443,414)
Property, plant, and equipment, net	$	189,748	$	207,816

Depreciation expense	Three Months Ended September 30,				Nine Months Ended September 30,
In thousands	2021		2020		2021		2020
Depreciation expense	$	12,389	$	12,893	$	37,338	$	38,818