Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jul. 05, 2015	Jun. 29, 2014	Mar. 30, 2014	Jul. 05, 2015	Jun. 29, 2014
Segment Reporting Information [Line Items]
Restructuring and other		$ (385)	$ 572		$ (385)	$ 572
Contingent consideration adjustment					(1,600)
Gain from the sale of an equity investment					(5,406)
Stock based compensation expense				$ 6,600
ZTEC Instruments, Inc.
Segment Reporting Information [Line Items]
Contingent consideration adjustment		1,600			1,600
Universal Robots
Segment Reporting Information [Line Items]
Acquisition related costs					1,000
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge		330	879		1,176	3,972
Restructuring and other			426			426
Total		330	1,305		1,176	4,398
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge		7,702	440		7,765	1,181
Restructuring and other			146			146
Total		7,702	586		7,765	1,327
Industrial Automation
Segment Reporting Information [Line Items]
Cost of revenues-inventory step-up	[1]	595			595
Total		595			595
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge		6,409	3,713		6,940	9,918
Restructuring and other		305			305
Total		6,714	$ 3,713		7,245	9,918
Corporate And Eliminations
Segment Reporting Information [Line Items]
Total		(1,264)			(6,046)	6,598
Corporate And Eliminations | Other (income) expense, net
Segment Reporting Information [Line Items]
Gain from the sale of an equity investment		(624)			(5,406)
Corporate And Eliminations | Selling, General and Administrative Expenses
Segment Reporting Information [Line Items]
Stock based compensation expense	[2]					$ 6,598
Corporate And Eliminations | ZTEC Instruments, Inc. | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment		(1,600)			(1,600)
Corporate And Eliminations | Universal Robots | Restructuring and other
Segment Reporting Information [Line Items]
Acquisition related costs		$ 960			$ 960

[1] Included in the cost of revenues for the three and six months ended July 5, 2015 is the cost for purchase accounting inventory step-up.

[2] Expense related to the January 2014 retirement of Teradyne's former chief executive officer; see Note J: "Stock-Based Compensation".