Schedule of Segment Reporting Information by Segment Charges (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-provision for excess and obsolete inventory	$ 1,378	$ 3,085	$ 1,878	$ 9,254
Restructuring and other	282	(4)	416	315
Total	1,660	3,081	2,294	9,569
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-provision for excess and obsolete inventory	2,059	2,018	6,125	4,134
Cost of revenues-inventory step-up				6,089
Restructuring and other		236	82	236
Total	2,059	2,254	6,207	10,459
System Test
Segment Reporting Information [Line Items]
Cost of revenues-provision for excess and obsolete inventory	404	378	1,613	3,020
Restructuring and other	1,055	451	1,430	451
Total	1,459	829	3,043	3,471
Corporate And Eliminations
Segment Reporting Information [Line Items]
Restructuring and other	(448)		(448)	(8,406)
Total	$ (448)		$ (448)	$ (8,406)