Condensed Consolidated Statements of Cash Flows - Unaudited - USD ($) $ in Thousands	9 Months Ended
	Oct. 02, 2020	Sep. 27, 2019
Cash flows from operating activities:
Net income (loss)	$ 61,831	$ 85,312
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	59,005	57,397
Debt related charges included in interest expense	3,145	5,280
Stock-based compensation	6,229	6,894
Non-cash charges related to customer bankruptcy	562	0
Non-cash lease expense	5,824	5,555
Non-cash (gain) loss on equity investments	(3,954)	666
Other non-cash gains	(184)	(1,088)
Deferred income taxes	42	(1,086)
Gain on sale of discontinued operations	0	(4,974)
Changes in operating assets and liabilities, net of acquisition:
Accounts receivable	42,096	(29,962)
Inventories	10,272	(8,567)
Contract assets, prepaid expenses and other assets	(47,350)	(16,384)
Accounts payable	(5,152)	17,760
Accrued expenses and other liabilities	(13,780)	(8,988)
Income taxes	(8,347)	4,162
Net cash provided by operating activities	110,239	111,977
Cash flows from investing activities:
Acquisition of property, plant and equipment	(35,182)	(24,704)
Purchase of intangible asset	(4,607)	0
Proceeds from sale of property, plant and equipment	76	5
Purchase of equity investments	0	(417)
Acquisitions, net	(5,219)	0
Proceeds from sale of discontinued operations	0	4,734
Net cash used in investing activities	(44,932)	(20,382)
Cash flows from financing activities:
Principal payments of long-term debt	(28,125)	(97,125)
Proceeds from senior secured revolving line of credit	185,000	20,000
Payments of senior secured revolving line of credit	(135,000)	(25,000)
Proceeds from the exercise of stock options	3,123	2,654
Payment of debt issuance costs	(431)	0
Tax withholdings related to net share settlements of restricted stock unit awards	(2,869)	(2,961)
Net cash provided by (used in) financing activities	21,698	(102,432)
Effect of foreign currency exchange rates on cash and cash equivalents	(597)	(13)
Net increase (decrease) in cash and cash equivalents	86,408	(10,850)
Cash and cash equivalents, beginning of period	13,535	25,569
Cash and cash equivalents, end of period	$ 99,943	$ 14,719