Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jul. 01, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 42,354	$ 47,062
Marketable securities	93,340	82,899
Accounts receivable, net of allowances of $55 and $73, respectively	46,966	39,457
Inventories	48,862	38,837
Inventories-delivered systems	1,674	2,457
Prepaid expenses and other	8,887	5,667
Total current assets	242,083	216,379
Property, plant and equipment, net	42,018	44,226
Goodwill	9,756	8,940
Intangible assets, net	309	412
Deferred income tax assets	17,827	17,399
Other assets	399	474
Total assets	312,392	287,830
Current liabilities:
Accounts payable	14,925	11,342
Accrued payroll and related expenses	10,615	12,656
Deferred revenue	11,045	9,168
Other current liabilities	7,368	8,047
Income taxes payable	1,258	813
Total current liabilities	45,211	42,026
Deferred revenue	776	816
Income taxes payable	882	841
Deferred tax liability	21	20
Other long-term liabilities	375	353
Total liabilities	47,265	44,056
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.001 par value; 3,000,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.001 par value, 47,000,000 shares authorized: 25,474,086 and 25,070,889, respectively, issued and outstanding	25	25
Additional paid-in capital	275,908	271,969
Accumulated deficit	(7,449)	(22,174)
Accumulated other comprehensive income (loss)	(3,357)	(6,046)
Total stockholders’ equity	265,127	243,774
Total liabilities and stockholders’ equity	$ 312,392	$ 287,830