Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016		Dec. 26, 2015
Cash flows from operating activities:
Net income	$ 32,843	$ 3,039	[1]	$ 250
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on disposal of microwave equipment segment	278	221		3,573
Gain on sale of facility				(3,198)
Operating cash flows of discontinued operations				(1,039)
Depreciation and amortization	9,195	10,412		11,273
Share-based compensation expense	7,007	7,143		6,755
Amortization of inventory step-up	1,404
Accrued retiree benefits	322	672		2,185
Deferred income taxes	(3,791)	(1,065)		222
Adjustment to contingent consideration liability	1,423
Changes in other assets	1,501	415		(326)
(Gain) loss on disposal and impairment of fixed assets	(42)	31		311
Changes in accrued liabilities	979	162		127
Changes in current assets and liabilities, excluding effects from acquisitions and divestitures:
Accounts receivable	(3,259)	(4,617)		8,970
Inventories	(12,196)	4,608		(5,743)
Accrued compensation, warranty and other liabilities	937	(1,544)		(3,740)
Accounts payable	4,157	5,678		3,376
Deferred profit	(442)	3,309		(3,108)
Other current assets	952	(1,959)		2,420
Income taxes payable	(1,518)	(1,957)		(828)
Net cash provided by operating activities	39,750	24,548		21,480
Cash flows from investing activities, excluding effects from acquisitions and divestitures:
Sales and maturities of short-term investments	47,671	20,230		155
Purchases of short-term investments	(37,010)	(50,568)		(656)
Payment for purchase of Kita, net of cash received	(11,716)
Purchases of property, plant and equipment	(6,093)	(3,452)		(6,586)
Net cash received from disposition of business segment				4,881
Net cash received from sale of facility and assets	104	874		33,314
Investing cash flows of discontinued operations				(74)
Net cash provided by (used in) investing activities	(7,044)	(32,916)		31,034
Cash flows from financing activities:
Cash dividends paid	(6,577)	(6,351)		(6,215)
Repayments of long-term debt	(1,631)
Issuance (repurchases) of common stock, net	10,353	(356)		1,233
Net cash provided by (used in) financing activities	2,145	(6,707)		(4,982)
Effect of exchange rate changes on cash and cash equivalents	3,390	(4,250)		(3,047)
Net increase (decrease) in cash and cash equivalents	38,241	(19,325)		44,485
Cash and cash equivalents at beginning of year	96,045	115,370		70,885
Cash and cash equivalents at end of year	134,286	96,045		115,370
Supplemental disclosure of cash flow information:
Cash paid (refunded) during the year for income taxes	7,094	6,808		(253)
Dividends declared but not yet paid	1,705	1,606		1,573
Fixed asset additions included in accounts payable	260	445
Inventory capitalized as capital assets	190	201		315
Capitalized facility under build-to-suit lease				$ 682

[1] As a result of the adoption of ASU 2016-09, in the fourth quarter of 2016, certain amounts in the first three quarters have been restated as if the new accounting guidance was adopted starting with the first day of our 2016 fiscal year. The impact of these restatements was not significant.