Restructuring And Other, Net (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 01, 2012
Restructuring Cost and Reserve [Line Items]
Expected lease accruals payment	$ 0.8
Future lease commitments net of expected sublease income	0.4
Lease expiration date	2013
Remaining accrual for lease payments	1.7
Contingent consideration payment	5.8
Q1 2011 Activity [Member] | Semiconductor Test [Member]
Restructuring Cost and Reserve [Line Items]
Reduction in employees headcount	5
Q1 2011 Actions [Member] | Semiconductor Test [Member]
Restructuring Cost and Reserve [Line Items]
Severance benefit and charges	0.6
Q2 2010 Actions [Member] | Semiconductor Test [Member]
Restructuring Cost and Reserve [Line Items]
Severance benefit and charges	0.2
Q4 2010 Actions [Member] | Semiconductor Test [Member]
Restructuring Cost and Reserve [Line Items]
Severance benefit and charges	0.1
Pre-2011 Actions [Member] | Systems Test Group [Member]
Restructuring Cost and Reserve [Line Items]
Changes in estimated exit costs	(0.4)
Other [Member]
Restructuring Cost and Reserve [Line Items]
Fair value adjustment to decrease acquisition contingent consideration	1.9
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Estimated undiscounted range of outcomes for contingent consideration	66.0
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Estimated undiscounted range of outcomes for contingent consideration	$ 54.0