Schedule of Segment Information (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
Segment Reporting Information [Line Items]
Net revenues	$ 433,376		$ 463,394		$ 1,142,632		$ 1,408,346
Income (loss) before income taxes	87,552	[1],[2]	103,025	[1],[2]	166,483	[1],[2]	296,261	[1],[2]
Semiconductor Test
Segment Reporting Information [Line Items]
Net revenues	304,131		310,979		808,068		943,625
Income (loss) before income taxes	68,932	[1],[2]	55,348	[1],[2]	141,304	[1],[2]	181,594	[1],[2]
Wireless Test
Segment Reporting Information [Line Items]
Net revenues	93,132		118,571		226,116		261,827
Income (loss) before income taxes	27,575	[1],[2]	58,902	[1],[2]	41,491	[1],[2]	97,729	[1],[2]
System Test
Segment Reporting Information [Line Items]
Net revenues	36,113		33,844		108,448		202,894
Income (loss) before income taxes	(2,462)	[1],[2]	(2,642)	[1],[2]	(153)	[1],[2]	30,964	[1],[2]
Corporate And Eliminations
Segment Reporting Information [Line Items]
Income (loss) before income taxes	$ (6,493)	[1],[2]	$ (8,583)	[1],[2]	$ (16,159)	[1],[2]	$ (14,026)	[1],[2]

[1] Pension and post retirement actuarial gains and losses, interest income, and interest expense and other are included in Corporate and Eliminations.

[2] Included in the income (loss) before income taxes for each of the segments are charges and credits for the three and nine months ended September 29, 2013 and September 30, 2012 that include restructuring and other, and provision for excess and obsolete inventory, as follows: