Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Current assets:
Cash and cash equivalents	$ 70,885	$ 51,668
Short-term investments	1,155	1,200
Accounts receivable, net	73,646	58,164
Inventories:
Raw materials and purchased parts	26,734	27,668
Work in process	21,738	16,941
Finished goods	7,073	10,800
Total inventories	55,545	55,409
Deferred income taxes	4,406	5,516
Other current assets	9,180	8,619
Current assets of discontinued video camera segment		6,272
Total current assets	214,817	186,848
Property, plant and equipment, at cost:
Land and land improvements	11,762	12,285
Buildings and building improvements	31,123	31,731
Machinery and equipment	42,352	42,105
Property plant and equipment, gross	85,237	86,121
Less accumulated depreciation and amortization	(53,383)	(50,325)
Net property, plant and equipment	31,854	35,796
Goodwill	63,132	71,313
Intangible assets, net	33,087	45,315
Other assets	5,928	5,720
Noncurrent assets of discontinued video camera segment		431
Total consolidated assets	348,818	345,423
Current liabilities:
Accounts payable	25,964	25,292
Accrued compensation and benefits	19,643	14,271
Accrued warranty	6,184	5,155
Deferred profit	7,445	6,066
Income taxes payable	3,133	805
Other accrued liabilities	7,184	7,675
Current liabilities of discontinued video camera segment		1,747
Total current liabilities	69,553	61,011
Accrued retirement benefits	13,815	10,841
Noncurrent income tax liabilities	7,321	7,463
Deferred income taxes	11,061	12,948
Commitments and contingencies
Stockholders' equity:
Preferred stock, $1 par value; 1,000 shares authorized, none issued
Common stock, $1 par value; 60,000 shares authorized, 25,692 shares issued and outstanding in 2014 and 25,080 shares in 2013	25,692	25,080
Paid-in capital	97,938	89,883
Retained earnings	134,152	131,546
Accumulated other comprehensive income (loss)	(10,714)	6,651
Total stockholders' equity	247,068	253,160
Total liabilities and stockholders' equity	$ 348,818	$ 345,423