Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016
Cash Flows from Operating Activities
Net Income	$ 5,938	$ 17,411
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation and amortization	11,530	11,331
Gain on divestitures	0	(18,815)
Stock-based compensation expense	3,164	1,985
Deferred income taxes	478	(3,144)
Provision for (recovery of) doubtful accounts	41	(24)
Other	(2,286)	(3,401)
Changes in Assets and Liabilities:
Accounts receivable	(5,767)	2,738
Inventories	(9,502)	(12,875)
Production cost of contracts	(1,777)	792
Other assets	938	7,690
Accounts payable	14,998	9,871
Accrued and other liabilities	(1,508)	(1,484)
Net Cash Provided by Operating Activities	16,247	12,075
Cash Flows from Investing Activities
Purchases of property and equipment	(16,242)	(7,619)
Proceeds from sale of assets	3	0
Proceeds from divestitures	0	55,272
Net Cash (Used in) Provided by Investing Activities	(16,239)	47,653
Cash Flows from Financing Activities
Borrowings from senior secured revolving credit facility	123,000	9,200
Repayments of senior secured revolving credit facility	(110,800)	(4,200)
Repayments of senior unsecured notes and term loans	(10,000)	(60,000)
Repayments of other debt	(3)	(14)
Net (cash paid) proceeds from issuance of common stock under stock plans	(2,265)	(992)
Net Cash Used in Financing Activities	(68)	(56,006)
Net (Decrease) Increase in Cash and Cash Equivalents	(60)	3,722
Cash and Cash Equivalents at Beginning of Period	7,432	5,454
Cash and Cash Equivalents at End of Period	$ 7,372	$ 9,176