Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 24, 2016	Dec. 26, 2015
Current assets:
Cash and cash equivalents	$ 37,421	$ 38,154
Marketable securities	81,106	44,931
Accounts receivable, net of allowances of $92 and $150, respectively	41,182	37,832
Inventories	39,260	47,749
Inventories-delivered systems	4,416	2,856
Prepaid expenses and other	5,835	6,592
Total current assets	209,220	178,114
Property, plant and equipment, net	44,324	44,493
Goodwill	9,665	9,415
Intangible assets, net	552	1,867
Deferred income tax assets	1,319	1,118
Other assets	526	533
Total assets	265,606	235,540
Current liabilities:
Accounts payable	8,562	11,675
Accrued payroll and related expenses	11,631	10,097
Deferred revenue	16,804	12,790
Other current liabilities	8,630	8,878
Income taxes payable	278	1,771
Total current liabilities	45,905	45,211
Deferred revenue	639	827
Income taxes payable	848	775
Deferred tax liability	709	521
Other long-term liabilities	866	878
Total liabilities	48,967	48,212
Commitments and contingencies (Note 11)
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: 24,897,878 and 24,224,286, respectively, issued and outstanding	25	24
Additional paid-in capital	268,553	258,715
Accumulated deficit	(48,828)	(66,209)
Accumulated other comprehensive income	(3,111)	(5,202)
Total stockholders’ equity	216,639	187,328
Total liabilities and stockholders’ equity	$ 265,606	$ 235,540