Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Cash Flows from Operating Activities
Net Income	$ 23,590	$ 8,362
Net Cash Provided by Operating Activities:
Depreciation and amortization	20,751	18,635
Non-cash operating lease cost	1,972
Property and equipment impairment due to restructuring	0	5,784
Stock-based compensation expense	5,322	3,414
Deferred income taxes	113	3,446
(Recovery of) provision for doubtful accounts	(239)	344
Other	152	9,275
Changes in Assets and Liabilities:
Accounts receivable	(8,944)	10,771
Contract assets	(15,810)	(88,066)
Inventories	(8,723)	22,909
Production cost of contracts	(1,537)	(1,447)
Other assets	525	3,709
Accounts payable	8,806	22,610
Contract liabilities	(5,295)	15,108
Accrued and other liabilities	(614)	(1,452)
Net Cash Provided by Operating Activities	20,069	33,402
Cash Flows from Investing Activities
Purchases of property and equipment	(14,698)	(12,796)
Proceeds from sale of assets	0	117
Payments for acquisition of Certified Thermoplastics Co., LLC, net of cash acquired	0	(30,711)
Net Cash Used in Investing Activities	(14,698)	(43,390)
Cash Flows from Financing Activities
Borrowings from senior secured revolving credit facility	163,500	239,700
Repayments of senior secured revolving credit facility	(163,500)	(227,100)
Repayments of term loan	(6,570)	0
Repayments of other debt and finance lease obligations	(118)	0
Net cash paid upon issuance of common stock under stock plans	(2,204)	(1,189)
Net Cash (Used in) Provided by Financing Activities	(8,892)	11,411
Net (Decrease) Increase in Cash, Cash Equivalents, and Restricted Cash	(3,521)	1,423
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	10,263	2,150
Cash, Cash Equivalents, and Restricted Cash at End of Period	$ 6,742	$ 3,573