Schedule of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Oct. 02, 2022		Oct. 03, 2021		Oct. 02, 2022		Oct. 03, 2021		Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues		$ 827,073	[1]	$ 950,501	[1]	$ 2,423,209	[2]	$ 2,817,835
Income (loss) before income taxes	[3],[4]	226,197		297,755		645,148		905,774
Total assets		3,319,906	[5]	3,762,182	[5]	3,319,906	[5]	3,762,182	[5]	$ 3,809,425
Semiconductor Test
Segment Reporting Information [Line Items]
Revenues		575,704		688,232		1,599,392		2,050,271
Income (loss) before income taxes	[3],[4]	182,625		265,017		510,112		778,687
Total assets	[5]	1,366,478		1,251,549		1,366,478		1,251,549
System Test
Segment Reporting Information [Line Items]
Revenues		116,154	[1]	102,605	[1]	369,525	[2]	340,261
Income (loss) before income taxes	[3],[4]	40,201		31,773		135,566		116,788
Total assets	[5]	192,684		147,970		192,684		147,970
Industrial Automation
Segment Reporting Information [Line Items]
Revenues		89,067		91,014		292,772		263,151
Income (loss) before income taxes	[3],[4]	(3,992)		(4,226)		(15,496)		(14,586)
Total assets	[5]	614,558		696,792		614,558		696,792
Wireless Test
Segment Reporting Information [Line Items]
Revenues		46,148	[1]	68,713	[1]	161,520	[2]	164,504
Income (loss) before income taxes	[3],[4]	12,647		31,726		56,659		63,810
Total assets	[5]	110,484		119,568		110,484		119,568
Corporate And Eliminations
Segment Reporting Information [Line Items]
Revenues		0		(63)		0		(352)
Income (loss) before income taxes	[3],[4]	(5,284)		(26,535)		(41,693)		(38,925)
Total assets	[5]	$ 1,035,702		$ 1,546,303		$ 1,035,702		$ 1,546,303

[1] Includes $3.8 million and $3.8 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 $11.1 million and $11.1 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 nine months ended October 3, 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 nine months ended October 3, 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.