Disaggregated Revenue by Primary Geographical Market, Major Product Line and Timing of Revenue Recognition (Detail) - USD ($) $ in Thousands		3 Months Ended
		Apr. 04, 2021	Mar. 29, 2020
Disaggregation of Revenue [Line Items]
Total	[1]	$ 781,606	$ 704,355
Semiconductor Test
Disaggregation of Revenue [Line Items]
Total		528,063	484,489
System Test
Disaggregation of Revenue [Line Items]
Total	[1]	132,837	116,076
Industrial Automation
Disaggregation of Revenue [Line Items]
Total		79,951	60,305
Wireless Test
Disaggregation of Revenue [Line Items]
Total	[1]	40,898	43,485
Corporate and Other
Disaggregation of Revenue [Line Items]
Total	[1]	(143)
Point in Time
Disaggregation of Revenue [Line Items]
Total	[1]	701,084	626,933
Point in Time | System Test
Disaggregation of Revenue [Line Items]
Total	[1]	119,314	100,712
Point in Time | Wireless Test
Disaggregation of Revenue [Line Items]
Total	[1]	37,880	41,056
Point in Time | Corporate and Other
Disaggregation of Revenue [Line Items]
Total	[1]	(143)
Over Time
Disaggregation of Revenue [Line Items]
Total	[1]	80,522	77,422
Over Time | System Test
Disaggregation of Revenue [Line Items]
Total	[1]	13,523	15,364
Over Time | Wireless Test
Disaggregation of Revenue [Line Items]
Total	[1]	3,018	2,429
Americas
Disaggregation of Revenue [Line Items]
Total	[1]	81,010	76,939
Americas | System Test
Disaggregation of Revenue [Line Items]
Total	[1]	27,659	28,291
Americas | Wireless Test
Disaggregation of Revenue [Line Items]
Total	[1]	5,769	4,688
Americas | Corporate and Other
Disaggregation of Revenue [Line Items]
Total	[1]	(143)
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total	[1]	54,980	58,242
Europe, Middle East and Africa | System Test
Disaggregation of Revenue [Line Items]
Total	[1]	5,658	7,768
Europe, Middle East and Africa | Wireless Test
Disaggregation of Revenue [Line Items]
Total	[1]	1,597	992
Asia Pacific
Disaggregation of Revenue [Line Items]
Total	[1]	645,617	569,174
Asia Pacific | System Test
Disaggregation of Revenue [Line Items]
Total	[1]	99,520	80,017
Asia Pacific | Wireless Test
Disaggregation of Revenue [Line Items]
Total	[1]	33,532	37,805
SOC | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	420,230	400,139
SOC | Point in Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	364,190	348,044
SOC | Over Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	56,040	52,095
SOC | Americas | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	20,779	17,386
SOC | Europe, Middle East and Africa | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	12,215	20,021
SOC | Asia Pacific | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	387,236	362,732
Memory | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	107,833	84,350
Memory | Point in Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	101,892	79,398
Memory | Over Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	5,941	4,952
Memory | Americas | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	3,420	6,896
Memory | Europe, Middle East and Africa | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	364	1,344
Memory | Asia Pacific | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	[1]	104,049	76,110
Universal Robots (UR) | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	65,601	49,697
Universal Robots (UR) | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	64,007	47,502
Universal Robots (UR) | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	1,594	2,195
Universal Robots (UR) | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	18,153	14,743
Universal Robots (UR) | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	29,615	24,037
Universal Robots (UR) | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	17,833	10,917
MiR | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	14,131	9,138
MiR | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	14,064	9,097
MiR | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	67	41
MiR | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	5,153	3,465
MiR | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	5,531	4,080
MiR | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	3,447	1,593
Autoguide LLC [Member] | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	219	1,470
Autoguide LLC [Member] | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	(120)	1,124
Autoguide LLC [Member] | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	339	346
Autoguide LLC [Member] | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	[1]	$ 219	$ 1,470

[1] Includes $3.1 million and $1.8 million in 2021 and 2020, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “Revenue from Contracts with Customers.”