Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2025	Dec. 28, 2024	Dec. 30, 2023
Cash flows from operating activities:
Net income (loss)	$ (74,273)	$ (69,818)	$ 28,156
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Net accretion on investments	(1,457)	(1,254)	(1,364)
Loss on extinguishment of debt	0	241	369
Pension curtailment gain	(2,159)	0	0
Depreciation and amortization	50,685	52,487	49,744
Share-based compensation expense	23,042	20,740	17,237
Inventory related charges	8,211	4,977	5,619
Amortization of debt discounts and issuance costs	422	8	146
Changes in accrued retiree medical benefits	(1,817)	(1,589)	(540)
Deferred income taxes	(1,802)	(3,722)	(4,774)
Impairment charge related to equity investment	0	903	0
Change in fair value of contingent consideration liability	(1,700)	0	0
Changes in other assets	426	(3,831)	(13,286)
Amortization of cloud-based software implementation costs	2,836	2,836	2,800
(Gain) loss from sale of property, plant and equipment	141	176	(4)
Changes in other accrued liabilities	(175)	(1,309)	(702)
Operating lease right-of-use assets	7,148	5,812	7,656
Changes in current assets and liabilities:
Customer advances	(208)	(1,835)	(2,309)
Accounts receivable, net	(14,466)	34,850	61,899
Inventories	4,280	6,374	12,839
Accrued compensation, warranty and other liabilities	8,614	(15,449)	(14,897)
Accounts payable	10,296	(3,560)	(21,356)
Deferred profit	3,707	26	(4,447)
Other current assets	15,353	(16,148)	10,920
Income taxes payable	1,450	(2,234)	(24,782)
Current and long-term operating lease liabilities	(6,862)	(5,903)	(7,454)
Net cash provided by operating activities	31,692	2,778	101,470
Cash flows from investing activities:
Purchases of property, plant and equipment	(20,958)	(10,634)	(16,053)
Net cash received from sale of assets	504	107	216
Purchases of short-term investments	(263,417)	(78,573)	(97,290)
Sales and maturities of short-term investments	63,762	114,228	152,649
Settlement of net investment hedge	(2,145)	(3,212)	0
Net cash provided by (used in) investing activities	(257,017)	21,916	(30,210)
Cash flows from financing activities:
Proceeds from revolving line of credit, revolving credit facility and convertible notes	296,295	0	0
Payment of debt issuance costs	(9,435)	0	0
Purchase of capped calls related to convertible notes	(31,395)	0	0
Repayments of long-term debt	(1,733)	(31,324)	(38,788)
Payments on finance lease liabilities	(7)	(24)	(52)
Acquisition of treasury stock	(8,586)	(26,986)	(23,641)
Net issuance (repurchases) of stock, including awards settled in cash	1,187	(701)	(5,656)
Net cash provided by (used in) financing activities	246,326	(59,035)	(68,137)
Effect of exchange rate changes on cash and cash equivalents
Effect of exchange rate changes on cash and cash equivalents	(355)	(4,776)	60
Net decrease in cash and cash equivalents	20,646	(39,117)	3,183
Cash and cash equivalents at beginning of year	206,407	245,524	242,341
Cash and cash equivalents at end of year	227,053	206,407	245,524
Supplemental disclosure of cash flow information:Cash Flow Information [Abstract]
Cash paid for income taxes, net of refunds	(2,829)	24,926	44,276
Cash paid for interest	536	803	3,424
Property, plant and equipment purchases included in accounts payable	307	454	124
Inventory capitalized as capital assets	1,241	1,765	1,215
Tignis, Inc [Member]
Cash flows from investing activities:
Payment for purchase of business, net of cash received	(34,763)	0	0
MCT Worldwide, LLC [Member]
Cash flows from investing activities:
Payment for purchase of business, net of cash received	0	0	(26,331)
Equiptest Engineering Pte Ltd. [Member]
Cash flows from investing activities:
Payment for purchase of business, net of cash received	$ 0	$ 0	$ (43,401)