Restructuring and Other Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 Employee	Oct. 02, 2011
Restructuring Cost and Reserve
Contingent consideration payment	$ 44.0
Business acquisition, acquisition costs		1.3
Pension settlement charge related to non-U.S.		0.7
Remaining accrual for lease payments	1.3
Lease expiration date	Dec. 31, 2013
Future lease commitments net of expected sublease income	0.2
Severance benefit and charges	0.7
Reduction in employees headcount	9
Minimum
Restructuring Cost and Reserve
Estimated undiscounted range of outcomes for contingent consideration	16.0
Maximum
Restructuring Cost and Reserve
Estimated undiscounted range of outcomes for contingent consideration	17.0
Q3 2012 Activity | Systems Test Group
Restructuring Cost and Reserve
Severance benefit and charges	0.5
Reduction in employees headcount	7
Q3 2012 Activity | Wireless Test
Restructuring Cost and Reserve
Severance benefit and charges	0.2
Reduction in employees headcount	2
Other
Restructuring Cost and Reserve
Fair value adjustment to decrease acquisition contingent consideration	$ 8.4