Disaggregated Revenue by Primary Geographical Market, Major Product Line and Timing of Revenue Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2025	Sep. 29, 2024	Sep. 28, 2025	Sep. 29, 2024
Disaggregation of Revenue [Line Items]
Total	$ 769,210	$ 737,298	$ 2,106,687	$ 2,066,996
Product Test
Disaggregation of Revenue [Line Items]
Total	88,256	80,129	247,498	237,240
Point in Time
Disaggregation of Revenue [Line Items]
Total	662,649	638,836	1,793,889	1,764,241
Point in Time \| Product Test
Disaggregation of Revenue [Line Items]
Total	69,579	64,305	192,296	189,987
Over Time
Disaggregation of Revenue [Line Items]
Total	106,561	98,462	312,798	302,755
Over Time \| Product Test
Disaggregation of Revenue [Line Items]
Total	18,677	15,824	55,202	47,253
Asia Pacific
Disaggregation of Revenue [Line Items]
Total	612,779	569,818	1,651,845	1,570,375
Asia Pacific \| Product Test
Disaggregation of Revenue [Line Items]
Total	25,136	29,775	85,583	86,079
Americas
Disaggregation of Revenue [Line Items]
Total	99,432	104,684	298,612	305,395
Americas \| Product Test
Disaggregation of Revenue [Line Items]
Total	55,225	43,494	138,239	116,799
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total	56,999	62,796	156,230	191,226
Europe, Middle East and Africa \| Product Test
Disaggregation of Revenue [Line Items]
Total	7,895	6,860	23,676	34,362
System on-a-Chip \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	440,216	392,355	1,243,194	1,108,247
System on-a-Chip \| Point in Time \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	367,404	323,507	1,030,682	896,635
System on-a-Chip \| Over Time \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	72,812	68,848	212,512	211,612
System on-a-Chip \| Asia Pacific \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	409,959	364,476	1,132,944	1,016,674
System on-a-Chip \| Americas \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	14,432	17,150	65,404	59,912
System on-a-Chip \| Europe, Middle East and Africa \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	15,825	10,729	44,846	31,661
Memory \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	128,062	150,379	298,413	389,305
Memory \| Point in Time \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	118,878	143,581	272,534	367,679
Memory \| Over Time \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	9,184	6,798	25,879	21,626
Memory \| Asia Pacific \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	126,534	137,890	292,683	357,993
Memory \| Americas \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	1,029	1,325	4,023	13,631
Memory \| Europe, Middle East and Africa \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	499	11,164	1,707	17,681
IST \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	37,589	25,784	98,642	65,652
IST \| Point in Time \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	33,575	20,771	85,294	49,868
IST \| Over Time \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	4,014	5,013	13,348	15,784
IST \| Asia Pacific \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	37,298	23,844	95,782	61,014
IST \| Americas \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	291	1,940	2,860	4,638
IST \| Europe, Middle East and Africa \| Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	0	0	0	0
Universal Robots (UR) \| Robotics
Disaggregation of Revenue [Line Items]
Total	75,087	88,651	218,940	266,552
Universal Robots (UR) \| Point in Time \| Robotics
Disaggregation of Revenue [Line Items]
Total	73,213	86,672	213,083	260,072
Universal Robots (UR) \| Over Time \| Robotics
Disaggregation of Revenue [Line Items]
Total	1,874	1,979	5,857	6,480
Universal Robots (UR) \| Asia Pacific \| Robotics
Disaggregation of Revenue [Line Items]
Total	13,852	13,833	44,853	48,615
Universal Robots (UR) \| Americas \| Robotics
Disaggregation of Revenue [Line Items]
Total	28,455	40,775	88,086	110,415
Universal Robots (UR) \| Europe, Middle East and Africa \| Robotics
Disaggregation of Revenue [Line Items]
Total	$ 32,780	$ 34,043	$ 86,001	$ 107,522