OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2019

Changes in allowance for doubtful accounts

Changes in allowance for doubtful accounts are summarized as follows (in thousands):



	Years Ended December 31,
	2019			2018			2017
Balances at beginning of period	$	245		$	215		$	237
Additions - charged to expense	113			104			168
Deductions - write offs, net of recoveries	(172		)	(74		)	(190		)
Balances at end of period	$	186		$	245		$	215

Schedule of cash and cash equivalents

The foreign cash balances are summarized as follows (in thousands):



	As of December 31,
	2019	2018
European Union Euros	1,773	1,615
Swiss Francs	124	156
Canadian Dollars	88	—
Australian Dollars	54	—

Schedule of property and equipment

We provide for depreciation primarily using the straight-line method by charges to income in amounts that allocate the cost of property and equipment over their estimated useful lives as follows:



Asset Classification	Estimated Useful Life
Building	10 to 20 years
Machinery and equipment	2 to 10 years
Office furniture and equipment	3 to 7 years
Computer hardware and software	3 to 5 years
Leasehold and building improvements	5 to 15 years

Property and equipment, net, consisted of the following (in thousands):



	December 31,
	2019			2018
Land	$	694		$	377
Building	3,845			2,978
Machinery and equipment	28,777			33,087
Office furniture and equipment	1,345			1,687
Computer hardware and software	3,408			4,704
Leasehold and building improvements	10,558			9,953
Construction in progress	671			1,274
Property and equipment, gross	49,298			54,060
Less accumulated depreciation	(33,829		)	(38,079		)
Total property and equipment, net	$	15,469		$	15,981