Certain Balance Sheet Components

3 Months Ended

Mar. 31, 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	March 31, 2021		December 31, 2020
Trade receivables (net of allowance of $1,136 and $1,312)	$	319,052	$	318,269
Unbilled receivables	46,774		51,559
Total accounts receivable, net	$	365,826	$	369,828

Allowance for credit losses account activity	Three Months Ended March 31,
In thousands	2021		2020
Beginning balance	$	1,312	$	3,064
Provision for (release of) doubtful accounts, net	(67)		510
Accounts written-off	(79)		(415)
Effect of change in exchange rates	(30)		(113)
Ending balance	$	1,136	$	3,046

Inventories
In thousands	March 31, 2021		December 31, 2020
Raw materials	$	109,314	$	114,058
Work in process	9,287		8,094
Finished goods	50,811		60,225
Total inventories	$	169,412	$	182,377

Property, plant, and equipment, net
In thousands	March 31, 2021		December 31, 2020
Machinery and equipment	$	333,973	$	334,050
Computers and software	116,121		115,776
Buildings, furniture, and improvements	153,246		155,676
Land	13,900		14,303
Construction in progress, including purchased equipment	30,207		31,425
Total cost	647,447		651,230
Accumulated depreciation	(447,797)		(443,414)
Property, plant, and equipment, net	$	199,650	$	207,816

Depreciation expense	Three Months Ended March 31,
In thousands	2021		2020
Depreciation expense	$	12,837	$	12,866