Disaggregated Revenue by Primary Geographical Market, Major Product Line and Timing of Revenue Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Oct. 03, 2021		Sep. 27, 2020		Oct. 03, 2021		Sep. 27, 2020
Disaggregation of Revenue [Line Items]
Total	$ 950,501	[1]	$ 819,484	[1]	$ 2,817,835	[2],[3]	$ 2,362,500	[2]
Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	688,232		592,141		2,050,271	[3]	1,735,777
System Test
Disaggregation of Revenue [Line Items]
Total	102,605	[1]	118,169	[1]	340,261	[2],[3]	306,051	[2]
Industrial Automation
Disaggregation of Revenue [Line Items]
Total	91,014		68,711		263,151	[3]	187,792
Wireless Test
Disaggregation of Revenue [Line Items]
Total	68,713	[1]	40,504	[1]	164,504	[2],[3]	133,174	[2]
Corporate and Other
Disaggregation of Revenue [Line Items]
Total	(63)	[1]	(41)	[1]	(352)	[2]	(294)	[2]
Point in Time
Disaggregation of Revenue [Line Items]
Total	856,287	[1]	736,325	[1]	2,546,734	[2]	2,124,031	[2]
Point in Time | System Test
Disaggregation of Revenue [Line Items]
Total	88,155	[1]	101,045	[1]	295,666	[2]	259,498	[2]
Point in Time | Wireless Test
Disaggregation of Revenue [Line Items]
Total	65,409	[1]	37,901	[1]	154,908	[2]	125,304	[2]
Point in Time | Corporate and Other
Disaggregation of Revenue [Line Items]
Total	(63)	[1]	(41)	[1]	(352)	[2]	(294)	[2]
Over Time
Disaggregation of Revenue [Line Items]
Total	94,214	[1]	83,159	[1]	271,101	[2]	238,469	[2]
Over Time | System Test
Disaggregation of Revenue [Line Items]
Total	14,450	[1]	17,124	[1]	44,595	[2]	46,553	[2]
Over Time | Wireless Test
Disaggregation of Revenue [Line Items]
Total	3,304	[1]	2,603	[1]	9,596	[2]	7,870	[2]
Americas
Disaggregation of Revenue [Line Items]
Total	105,999	[1]	87,494	[1]	287,475	[2]	232,840	[2]
Americas | System Test
Disaggregation of Revenue [Line Items]
Total	34,560	[1]	35,140	[1]	98,475	[2]	91,924	[2]
Americas | Wireless Test
Disaggregation of Revenue [Line Items]
Total	11,352	[1]	5,211	[1]	24,228	[2]	15,253	[2]
Americas | Corporate and Other
Disaggregation of Revenue [Line Items]
Total	(63)	[1]	(41)	[1]	(352)	[2]	(294)	[2]
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total	74,711	[1]	45,447	[1]	189,291	[2]	147,678	[2]
Europe, Middle East and Africa | System Test
Disaggregation of Revenue [Line Items]
Total	5,288	[1]	4,495	[1]	18,279	[2]	16,919	[2]
Europe, Middle East and Africa | Wireless Test
Disaggregation of Revenue [Line Items]
Total	3,017	[1]	1,428	[1]	6,598	[2]	4,345	[2]
Asia Pacific
Disaggregation of Revenue [Line Items]
Total	769,791	[1]	686,543	[1]	2,341,069	[2]	1,981,982	[2]
Asia Pacific | System Test
Disaggregation of Revenue [Line Items]
Total	62,757	[1]	78,534	[1]	223,507	[2]	197,208	[2]
Asia Pacific | Wireless Test
Disaggregation of Revenue [Line Items]
Total	54,344	[1]	33,865	[1]	133,678	[2]	113,576	[2]
SOC | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	575,017	[1]	449,705	[1]	1,736,917	[2]	1,423,627	[2]
SOC | Point in Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	508,747	[1]	393,717	[1]	1,548,895	[2]	1,261,468	[2]
SOC | Over Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	66,270	[1]	55,988	[1]	188,022	[2]	162,159	[2]
SOC | Americas | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	29,119	[1]	17,678	[1]	71,562	[2]	51,315	[2]
SOC | Europe, Middle East and Africa | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	26,012	[1]	11,206	[1]	47,238	[2]	41,849	[2]
SOC | Asia Pacific | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	519,886	[1]	420,821	[1]	1,618,117	[2]	1,330,463	[2]
Memory | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	113,215	[1]	142,436	[1]	313,354	[2]	312,150	[2]
Memory | Point in Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	105,454	[1]	137,929	[1]	291,578	[2]	298,150	[2]
Memory | Over Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	7,761	[1]	4,507	[1]	21,776	[2]	14,000	[2]
Memory | Americas | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	2,281	[1]	3,730	[1]	9,373	[2]	11,481	[2]
Memory | Europe, Middle East and Africa | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	572	[1]	1,420	[1]	2,419	[2]	3,990	[2]
Memory | Asia Pacific | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	110,362	[1]	137,286	[1]	301,562	[2]	296,679	[2]
Universal Robots (UR) | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	77,750	[1]	53,209	[1]	219,428	[2]	146,457	[2]
Universal Robots (UR) | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	76,008	[1]	51,523	[1]	214,427	[2]	140,829	[2]
Universal Robots (UR) | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	1,742	[1]	1,686	[1]	5,001	[2]	5,628	[2]
Universal Robots (UR) | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	23,429	[1]	16,527	[1]	66,390	[2]	42,634	[2]
Universal Robots (UR) | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	34,667	[1]	22,211	[1]	97,507	[2]	64,158	[2]
Universal Robots (UR) | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	19,654	[1]	14,471	[1]	55,531	[2]	39,665	[2]
MiR | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	12,958	[1]	10,234	[1]	42,989	[2]	30,644	[2]
MiR | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	12,351	[1]	10,175	[1]	41,506	[2]	30,468	[2]
MiR | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	607	[1]	59	[1]	1,483	[2]	176	[2]
MiR | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	5,015	[1]	3,981	[1]	17,065	[2]	9,836	[2]
MiR | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	5,155	[1]	4,687	[1]	17,250	[2]	16,417	[2]
MiR | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	2,788	[1]	1,566	[1]	8,674	[2]	4,391	[2]
Autoguide LLC [Member] | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	306	[1]	5,268	[1]	734	[2]	10,691	[2]
Autoguide LLC [Member] | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	226	[1]	4,076	[1]	106	[2]	8,608	[2]
Autoguide LLC [Member] | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	80	[1]	1,192	[1]	628	[2]	2,083	[2]
Autoguide LLC [Member] | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	$ 306	[1]	$ 5,268	[1]	$ 734	[2]	$ 10,691	[2]

[1] Includes $3.8 million and $1.7 million in 2021 and 2020, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “Revenue from Contracts with Customers.

[2] Includes $11.1 million and $6.1 million in 2021 and 2020, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “Revenue from Contracts with Customers.

[3] The (loss) before income taxes for the nine months ended October 3, 2021 for Industrial Automation has been decreased and Corporate and Other has been increased to correctly eliminate a $10.1 million immaterial error in the three and six months ended July 4, 2021 related to intercompany charges. The error is not material to any historical periods.