Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
Segment Reporting Information [Line Items]
Goodwill impairment		$ 254,946		$ 254,946
Acquired intangible assets impairment		83,339		83,339
Restructuring and other-employee severance	$ 2,288	2,608	$ 4,799	4,195
Contingent consideration adjustment		1,300	2,133	2,478
Property insurance recovery				5,051
Universal Robots
Segment Reporting Information [Line Items]
Contingent consideration adjustment	1,500	800	2,100	1,900
Avionics Interface Technologies, LLC
Segment Reporting Information [Line Items]
Contingent consideration adjustment		600		600
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	1,624	2,234	2,943	5,919
Restructuring and other-employee severance	132	337	(133)	751
Industrial Automation
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	321		945
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	472	5,271	994	5,876
Restructuring and other-lease impairment			1,313
Goodwill impairment		254,946		254,946
Acquired intangible assets impairment		83,339		83,339
Restructuring and other-employee severance		967		967
Corporate And Eliminations
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	325		530
Property insurance recovery		(5,051)		(5,051)
Corporate And Eliminations | Universal Robots | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	$ 1,499	755	$ 2,133	1,928
Corporate And Eliminations | Impairment of fixed assets and expenses related to the Japan earthquake
Segment Reporting Information [Line Items]
Building impairment and other expenses		5,051		5,051
Corporate And Eliminations | Avionics Interface Technologies, LLC
Segment Reporting Information [Line Items]
Contingent consideration adjustment		$ 550		$ 550