Schedule of Segment Reporting Information by Segment Charges (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Restructuring and other					$ 5,800
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	5,218	[1]	18,433	[1]	10,370	[1]
Restructuring and other	1,016		386		2,142
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	4,168		4,271		1,090
Restructuring and other	1,431		451		(300)
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory step-up			6,089	[2]	12,178	[2]
Cost of revenues-inventory charge	7,206		4,145		141
Restructuring and other	82		236
Corporate And Eliminations
Segment Reporting Information [Line Items]
Restructuring and other	$ (449)		$ (8,794)		$ 4,901

[1] Included in the cost of revenues for the years ended December 31, 2012 and 2011 are charges for excess inventory provisions recorded primarily as a result of product transition.

[2] Included in the cost of revenues for the years ended December 31, 2012 and 2011 is the cost for purchase accounting inventory step-up.