Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jul. 03, 2016	Oct. 02, 2016	Dec. 31, 2015
Goodwill [Line Items]
Foreign currency translation adjustment		$ 5,122
Goodwill impairment loss		254,946
Goodwill		1,001,155	$ 996,033
Accumulated impairment losses		(762,566)	(507,620)
Goodwill		238,589	488,413
Semiconductor Test
Goodwill [Line Items]
Goodwill		260,540	260,540
Accumulated impairment losses		(260,540)	(260,540)
Industrial Automation
Goodwill [Line Items]
Foreign currency translation adjustment		5,122
Goodwill		220,097	214,975
Goodwill		220,097	214,975
System Test
Goodwill [Line Items]
Goodwill		158,699	158,699
Accumulated impairment losses		(148,183)	(148,183)
Goodwill		10,516	10,516
Wireless Test
Goodwill [Line Items]
Goodwill impairment loss	$ 254,946	254,946
Goodwill		361,819	361,819
Accumulated impairment losses		(353,843)	(98,897)
Goodwill	$ 7,976	$ 7,976	$ 262,922

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
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-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
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-URI http://asc.fasb.org/extlink&oid=64834752&loc=SL49117168-202975

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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-Subparagraph (b)
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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