Revenue - Disaggregation of Revenue from Contracts with Customers (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2023	Jul. 02, 2022	Jul. 01, 2023	Jul. 02, 2022
Disaggregation of Revenue [Line Items]
Total net revenues	$ 10,301	$ 9,307	$ 21,843	$ 13,752
TFE
Disaggregation of Revenue [Line Items]
Total net revenues	10,301	9,307	21,843	13,752
TFE | Systems, Upgrades and Spare Parts
Disaggregation of Revenue [Line Items]
Total net revenues	9,372	7,839	19,907	11,015
TFE | Field Service
Disaggregation of Revenue [Line Items]
Total net revenues	929	1,468	1,936	2,737
HDD | TFE
Disaggregation of Revenue [Line Items]
Total net revenues	10,280	9,177	21,804	13,563
HDD | TFE | Systems, Upgrades and Spare Parts
Disaggregation of Revenue [Line Items]
Total net revenues	9,351	7,756	19,868	10,879
HDD | TFE | Field Service
Disaggregation of Revenue [Line Items]
Total net revenues	929	1,421	1,936	2,684
DCP | TFE
Disaggregation of Revenue [Line Items]
Total net revenues		44		44
DCP | TFE | Systems, Upgrades and Spare Parts
Disaggregation of Revenue [Line Items]
Total net revenues		1		1
DCP | TFE | Field Service
Disaggregation of Revenue [Line Items]
Total net revenues		43		43
PV | TFE
Disaggregation of Revenue [Line Items]
Total net revenues	10	86	28	145
PV | TFE | Systems, Upgrades and Spare Parts
Disaggregation of Revenue [Line Items]
Total net revenues	10	82	28	135
PV | TFE | Field Service
Disaggregation of Revenue [Line Items]
Total net revenues	0	$ 4	0	$ 10
ASP | TFE
Disaggregation of Revenue [Line Items]
Total net revenues	11		11
ASP | TFE | Systems, Upgrades and Spare Parts
Disaggregation of Revenue [Line Items]
Total net revenues	11		$ 11
ASP | TFE | Field Service
Disaggregation of Revenue [Line Items]
Total net revenues	$ 0