Revenue - Disaggregation of Revenue from Contracts with Customers (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2022	Oct. 02, 2021	Oct. 01, 2022	Oct. 02, 2021
Disaggregation of Revenue [Line Items]
Total net revenues	$ 10,750	$ 7,998	$ 24,502	$ 22,605
Systems, upgrades and spare parts
Disaggregation of Revenue [Line Items]
Total net revenues	8,410	6,556	19,425	18,106
Field service
Disaggregation of Revenue [Line Items]
Total net revenues	2,340	1,442	5,077	4,499
HDD
Disaggregation of Revenue [Line Items]
Total net revenues	10,393	7,919	23,956	18,459
HDD | Systems, upgrades and spare parts
Disaggregation of Revenue [Line Items]
Total net revenues	8,233	6,495	19,112	14,034
HDD | Field service
Disaggregation of Revenue [Line Items]
Total net revenues	2,160	1,424	4,844	4,425
DCP
Disaggregation of Revenue [Line Items]
Total net revenues			44	17
DCP | Systems, upgrades and spare parts
Disaggregation of Revenue [Line Items]
Total net revenues			1	3
DCP | Field service
Disaggregation of Revenue [Line Items]
Total net revenues			43	14
PV
Disaggregation of Revenue [Line Items]
Total net revenues	257	79	402	279
PV | Systems, upgrades and spare parts
Disaggregation of Revenue [Line Items]
Total net revenues	77	61	212	219
PV | Field service
Disaggregation of Revenue [Line Items]
Total net revenues	180	$ 18	190	60
ASP
Disaggregation of Revenue [Line Items]
Total net revenues	100		100	3,850
ASP | Systems, upgrades and spare parts
Disaggregation of Revenue [Line Items]
Total net revenues	100		100	3,850
ASP | Field service
Disaggregation of Revenue [Line Items]
Total net revenues	$ 0		$ 0	$ 0