Revenue - Schedule of Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	$ 1,167	$ 1,167
Revenue	61,296	79,636
Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	7,354	9,604
Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	52,775	68,865
Combined ATS development and Wafer Services
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	1,167	1,167
Revenue	60,062	71,177
Combined ATS development and Wafer Services \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	6,120	1,145
Combined ATS development and Wafer Services \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	52,775	68,865
Advanced Technology Services (ATS) Development
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	1,167	1,167
Revenue	52,535	61,185
Advanced Technology Services (ATS) Development \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	6,036	0
Advanced Technology Services (ATS) Development \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	45,332	60,018
Time-and-materials and cost-plus-fixed-fee contracts
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	0	0
Revenue	37,079	42,496
Time-and-materials and cost-plus-fixed-fee contracts \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	1,204	0
Time-and-materials and cost-plus-fixed-fee contracts \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	35,875	42,496
Fixed price contracts
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	0	0
Revenue	14,289	17,522
Fixed price contracts \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	4,832	0
Fixed price contracts \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	9,457	17,522
Other
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	1,167	1,167
Revenue	1,167	1,167
Other \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	0	0
Other \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	0
Wafer Services
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	0	0
Revenue	7,527	9,992
Wafer Services \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	84	1,145
Wafer Services \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	7,443	8,847
Tools
Disaggregation of Revenue [Line Items]
Lease Revenue Per Topic 842	0	0
Revenue	1,234	8,459
Tools \| Point-in-Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	1,234	8,459
Tools \| Over Time
Disaggregation of Revenue [Line Items]
Topic 606 Revenue	$ 0	$ 0