Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Cash Flows from Operating Activities
Net Income	$ 8,362	$ 10,593
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation and amortization	18,635	17,149
Property and equipment impairment due to restructuring	5,784	0
Stock-based compensation expense	3,414	4,264
Deferred income taxes	3,446	(164)
Provision for doubtful accounts	344	125
Other	9,275	(2,217)
Changes in Assets and Liabilities:
Accounts receivable	10,771	(1,427)
Contract assets	(88,066)	0
Inventories	22,909	(15,529)
Production cost of contracts	(1,447)	(599)
Other assets	3,709	458
Accounts payable	22,610	13,801
Contract liabilities	15,108	0
Accrued and other liabilities	(1,452)	903
Net Cash Provided by Operating Activities	33,402	27,357
Cash Flows from Investing Activities
Purchases of property and equipment	(12,796)	(24,599)
Proceeds from sale of assets	117	3
Insurance recoveries related to property and equipment	0	288
Payments for acquisition of Lightning Diversion Systems, LLC, net of cash acquired	0	(59,178)
Payments for acquisition of Certified Thermoplastics Co., LLC, net of cash acquired	(30,711)	0
Net Cash Used in Investing Activities	(43,390)	(83,486)
Cash Flows from Financing Activities
Borrowings from senior secured revolving credit facility	239,700	320,500
Repayments of senior secured revolving credit facility	(227,100)	(255,800)
Repayments of term loan	0	(10,000)
Repayments of other debt	0	(3)
Net cash paid upon issuance of common stock under stock plans	(1,189)	(2,311)
Net Cash Provided by Financing Activities	11,411	52,386
Net Increase (Decrease) in Cash and Cash Equivalents	1,423	(3,743)
Cash and Cash Equivalents at Beginning of Period	2,150	7,432
Cash and Cash Equivalents at End of Period	$ 3,573	$ 3,689