Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Cash Flows from Operating Activities
Net Income	$ 15,287	$ 4,191
Net Cash Provided by Operating Activities:
Depreciation and amortization	13,759	12,315
Non-cash operating lease cost	1,373
Property and equipment impairment due to restructuring	0	4,375
Stock-based compensation expense	3,271	2,115
Deferred income taxes	181	3,966
Recovery of doubtful accounts	(391)	(30)
Other	(297)	9,050
Changes in Assets and Liabilities:
Accounts receivable	(1,145)	11,172
Contract assets	(13,862)	(81,663)
Inventories	(8,202)	29,417
Production cost of contracts	(1,161)	160
Other assets	473	1,475
Accounts payable	7,158	20,117
Contract liabilities	(3,962)	15,164
Accrued and other liabilities	(4,432)	(5,597)
Net Cash Provided by Operating Activities	8,050	26,227
Cash Flows from Investing Activities
Purchases of property and equipment	(7,566)	(7,513)
Proceeds from sale of assets	0	67
Payments for acquisition of Certified Thermoplastics Co., LLC, net of cash acquired	0	(30,993)
Net Cash Used in Investing Activities	(7,566)	(38,439)
Cash Flows from Financing Activities
Borrowings from senior secured revolving credit facility	106,800	189,600
Repayments of senior secured revolving credit facility	(104,300)	(175,000)
Repayments of term loan	(6,000)	0
Repayments of other debt and finance lease obligations	(65)	0
Net cash paid upon issuance of common stock under stock plans	(3,138)	(1,006)
Net Cash (Used in) Provided by Financing Activities	(6,703)	13,594
Net (Decrease) Increase in Cash, Cash Equivalents, and Restricted Cash	(6,219)	1,382
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	10,263	2,150
Cash, Cash Equivalents, and Restricted Cash at End of Period	$ 4,044	$ 3,532