Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jul. 03, 2016	Jul. 03, 2016	Dec. 31, 2015
Goodwill [Line Items]
Foreign currency translation adjustment		$ 3,743
Goodwill impairment loss	$ 254,946	254,946
Goodwill	999,776	999,776	$ 996,033
Accumulated impairment losses	(762,566)	(762,566)	(507,620)
Goodwill	237,210	237,210	488,413
Semiconductor Test
Goodwill [Line Items]
Goodwill	260,540	260,540	260,540
Accumulated impairment losses	(260,540)	(260,540)	(260,540)
Industrial Automation
Goodwill [Line Items]
Foreign currency translation adjustment		3,743
Goodwill	218,718	218,718	214,975
Goodwill	218,718	218,718	214,975
System Test
Goodwill [Line Items]
Goodwill	158,699	158,699	158,699
Accumulated impairment losses	(148,183)	(148,183)	(148,183)
Goodwill	10,516	10,516	10,516
Wireless Test
Goodwill [Line Items]
Goodwill impairment loss	254,946	254,946
Goodwill	361,819	361,819	361,819
Accumulated impairment losses	(353,843)	(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
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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-Paragraph 28
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