Schedule of Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 29, 2014		Jun. 30, 2013		Jun. 29, 2014		Jun. 30, 2013
Segment Reporting Information [Line Items]
Net revenues	$ 525,567		$ 428,889		$ 846,577		$ 709,256
Income (loss) before income taxes	121,392	[1],[2]	80,357	[1],[2]	119,519	[1],[2]	78,931	[1],[2]
Semiconductor Test
Segment Reporting Information [Line Items]
Net revenues	421,434		292,431		683,171		503,937
Income (loss) before income taxes	107,270	[1],[2]	58,606	[1],[2]	141,870	[1],[2]	72,372	[1],[2]
Wireless Test
Segment Reporting Information [Line Items]
Net revenues	68,699		99,386		89,909		132,984
Income (loss) before income taxes	14,229	[1],[2]	23,913	[1],[2]	(10,856)	[1],[2]	13,916	[1],[2]
System Test
Segment Reporting Information [Line Items]
Net revenues	35,434		37,072		73,497		72,335
Income (loss) before income taxes	(715)	[1],[2]	779	[1],[2]	(267)	[1],[2]	2,309	[1],[2]
Corporate And Eliminations
Segment Reporting Information [Line Items]
Income (loss) before income taxes	$ 608	[1],[2]	$ (2,941)	[1],[2]	$ (11,228)	[1],[2]	$ (9,666)	[1],[2]

[1] Pension and postretirement 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 six months ended June 29, 2014 and June 30, 2013 that include restructuring and other, and provision for excess and obsolete inventory, as follows: