Schedule of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jul. 03, 2022		Jul. 04, 2021		Jul. 03, 2022		Jul. 04, 2021		Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues		$ 840,766	[1]	$ 1,085,728	[1]	$ 1,596,136	[2]	$ 1,867,334	[2]
Income (loss) before income taxes	[3],[4]	238,592		384,026		418,951		608,019
Total assets		3,488,426	[5]	4,000,922	[5]	3,488,426	[5]	4,000,922	[5]	$ 3,809,425
Semiconductor Test
Segment Reporting Information [Line Items]
Revenues		541,348		833,976		1,023,688		1,362,039
Income (loss) before income taxes	[3],[4]	177,782		337,302		327,487		513,670
Total assets	[5]	1,449,878		1,518,941		1,449,878		1,518,941
System Test
Segment Reporting Information [Line Items]
Revenues		134,702	[1]	104,819	[1]	253,371	[2]	237,656	[2]
Income (loss) before income taxes	[3],[4]	54,042		33,954		95,365		85,015
Total assets	[5]	229,359		146,296		229,359		146,296
Industrial Automation
Segment Reporting Information [Line Items]
Revenues		101,055		92,186		204,244		172,137
Income (loss) before income taxes	[3],[4]	(6,406)		(9,837)		(11,504)		(22,804)
Total assets	[5]	644,099		687,022		644,099		687,022
Wireless Test
Segment Reporting Information [Line Items]
Revenues		63,854	[1]	54,893	[1]	115,372	[2]	95,791	[2]
Income (loss) before income taxes	[3],[4]	25,393		21,472		44,012		31,088
Total assets	[5]	118,445		117,702		118,445		117,702
Corporate And Eliminations
Segment Reporting Information [Line Items]
Revenues		(193)		(146)		(539)		(289)
Income (loss) before income taxes	[3],[4]	(12,219)		1,135		(36,409)		1,050
Total assets	[5]	$ 1,046,645		$ 1,530,961		$ 1,046,645		$ 1,530,961

[1] Includes $1.9 million and $4.2 million in 2022 and 2021, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “Revenue from Contracts with Customers.”

[2] Includes $4.2 million and $7.3 million in 2022 and 2021, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “Revenue from Contracts with Customers.”

[3] Included in Corporate and Eliminations are: legal and environmental fees, contingent consideration fair value adjustments, interest income, interest expense, severance charges, net foreign exchange gains (losses), acquisition related charges and compensation, pension, intercompany eliminations and for the three and six months ended July 4, 2021, loss on convertible debt conversions.

[4] Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges and, for the three and six months ended July 4, 2021, loss on convertible debt conversions.

[5] Total assets are attributable to each segment. Corporate assets consist of cash and cash equivalents, marketable securities, and certain other assets.