Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 25, 2016		Jun. 27, 2015
Cash flows from operating activities:
Net income (loss)	$ 696		$ (2,812)
Reconciliation of net income (loss) to net cash provided by operating activities operating activities:
Loss on disposal of assets	38
Loss on disposal of microwave communications equipment business	55		3,010
Operating cash flows of discontinued operations			(1,039)
Depreciation and amortization	5,365		5,776
Share-based compensation expense	3,608		3,444
Deferred income taxes	(740)		(1,149)
Asset impairment charge			279
Changes in other accrued liabilities	271		1,068
Changes in other assets	(30)		(158)
Changes in current assets and liabilities, excluding effects from divestitures:
Accounts receivable	(2,811)		1,069
Inventories	1,045		(5,682)
Other current assets	(1,362)		908
Accounts payable	514		3,565
Deferred profit	3,130		787
Income taxes payable	(2,647)		1,093
Accrued compensation, warranty and other liabilities	(1,170)		(6,409)
Net cash provided by operating activities	5,962		3,750
Cash flows from investing activities, excluding effects from divestitures:
Purchases of short-term investments	(14,554)		(453)
Sales and maturities of short-term investments	6,991		155
Purchases of property, plant and equipment	(1,767)		(2,199)
Cash received from sale of facility	813
Cash received from sale of microwave communications equipment business			5,339
Investing cash flows of discontinued operations			(74)
Net cash provided by (used in) investing activities	(8,517)		2,768
Cash flows from financing activities:
Cash dividends paid	(3,148)		(3,082)
Issuance (repurchases) of common stock, net	(1,560)		104
Net cash used in financing activities	(4,708)		(2,978)
Effect of exchange rate changes on cash and cash equivalents	606		(1,837)
Net increase (decrease) in cash and cash equivalents	(6,657)		1,703
Cash and cash equivalents at beginning of period	115,370	[1]	70,885
Cash and cash equivalents at end of period	108,713		72,588
Supplemental disclosure of cash flow information:
Cash paid (refunded) for income taxes	5,161		(534)
Inventory capitalized as property, plant and equipment	142		172
Dividends declared but not yet paid	$ 1,601		$ 1,566

[1] Derived from December 26, 2015 audited financial statements