Certain Balance Sheet Components

9 Months Ended

Sep. 30, 2019

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, 2019		December 31, 2018
Trade receivables (net of allowance of $3,786 and $6,331)	$	410,391	$	416,503
Unbilled receivables	58,086		20,658
Total accounts receivable, net	$	468,477	$	437,161

Allowance for doubtful accounts activity	Three Months Ended September 30,						Nine Months Ended September 30,
In thousands	2019			2018			2019			2018
Beginning balance	$	4,360		$	4,552		$	6,331		$	3,957
Provision for (release of) doubtful accounts, net	(1		)	(105		)	(1,739		)	1,149
Accounts written-off	(468		)	(624		)	(740		)	(1,129		)
Effect of change in exchange rates	(105		)	(1		)	(66		)	(155		)
Ending balance	$	3,786		$	3,822		$	3,786		$	3,822

Inventories
In thousands	September 30, 2019		December 31, 2018
Raw materials	$	123,964	$	133,398
Work in process	10,980		9,744
Finished goods	96,137		77,532
Total inventories	$	231,081	$	220,674

Property, plant, and equipment, net
In thousands	September 30, 2019			December 31, 2018
Machinery and equipment	$	316,787		$	315,974
Computers and software	107,907			104,290
Buildings, furniture, and improvements	148,870			146,071
Land	14,763			14,980
Construction in progress, including purchased equipment	51,306			49,682
Total cost	639,633			630,997
Accumulated depreciation	(413,975		)	(404,446		)
Property, plant, and equipment, net	$	225,658		$	226,551

Depreciation expense	Three Months Ended September 30,				Nine Months Ended September 30,
In thousands	2019		2018		2019		2018
Depreciation expense	$	12,528	$	12,489	$	37,506	$	38,729