Segment Information (Schedule Of Segment Reporting Information By Segment Charges) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 01, 2012	Apr. 03, 2011
Semiconductor Test [Member]
Segment Reporting Information [Line Items]
Cost of revenues-provision for excess and obsolete inventory	$ 212	$ 4,442
Restructuring and other, net		891
Total	212	5,333
Systems Test Group [Member]
Segment Reporting Information [Line Items]
Cost of revenues-provision for excess and obsolete inventory	889	185
Restructuring and other, net		(246)
Total	889	(61)
Wireless Test [Member]
Segment Reporting Information [Line Items]
Cost of revenues-provision for excess and obsolete inventory	473
Cost of revenues-inventory step-up	4,871
Total	5,344
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Restructuring and other, net	(1,825)	(232)
Total	$ (1,825)	$ (232)