Computation of Basic and Diluted Net Income Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Oct. 02, 2022	Oct. 03, 2021	Oct. 02, 2022	Oct. 03, 2021
Net Income Loss Per Common Share
Net income for basic and diluted net income per share		$ 183,485	$ 256,718	$ 543,200	$ 790,549
Weighted average common shares-basic		156,364	164,583	159,325	165,690
Convertible note hedge warrant shares	[1]	8,284	9,819	9,114	9,774
Incremental shares from assumed conversion of convertible notes	[2]	1,453	6,464	1,965	8,784
Employee stock purchase plan		23	13	23	10
Dilutive potential common shares		10,369	17,404	11,831	19,802
Weighted average common shares-diluted		166,733	181,987	171,156	185,492
Net income per common share-basic		$ 1.17	$ 1.56	$ 3.41	$ 4.77
Net income per common share-diluted		$ 1.1	$ 1.41	$ 3.17	$ 4.26
Restricted Stock Units
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements		564	1,035	673	1,147
Stock Options
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements		45	73	56	87

[1] Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price, multiplied by the number of warrant shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period.

[2] Incremental shares from assumed conversion of the convertible notes were calculated using the difference between the average Teradyne stock price for the period and the conversion price, multiplied by the number of convertible notes shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period.