Certain Balance Sheet Components

3 Months Ended

Mar. 31, 2020

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, 2020		December 31, 2019
Trade receivables (net of allowance of $3,046 and $3,064)	$	398,025	$	415,887
Unbilled receivables	65,588		57,038
Total accounts receivable, net	$	463,613	$	472,925

Allowance for doubtful accounts activity	Three Months Ended March 31,
In thousands	2020		2019
Beginning balance	$	3,064	$	6,331
Provision for (release of) doubtful accounts, net	510		(2,103)
Accounts written-off	(415)		(192)
Effect of change in exchange rates	(113)		10
Ending balance	$	3,046	$	4,046

Inventories
In thousands	March 31, 2020		December 31, 2019
Raw materials	$	133,285	$	120,861
Work in process	10,473		11,105
Finished goods	78,092		95,930
Total inventories	$	221,850	$	227,896

Property, plant, and equipment, net
In thousands	March 31, 2020		December 31, 2019
Machinery and equipment	$	311,771	$	323,003
Computers and software	111,501		109,924
Buildings, furniture, and improvements	150,847		149,471
Land	14,538		14,988
Construction in progress, including purchased equipment	45,596		54,490
Total cost	634,253		651,876
Accumulated depreciation	(408,328)		(418,648)
Property, plant, and equipment, net	$	225,925	$	233,228

Depreciation expense	Three Months Ended March 31,
In thousands	2020		2019
Depreciation expense	$	12,866	$	12,384