Restructuring and Other - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended		3 Months Ended						12 Months Ended
	Sep. 30, 2012 Employee	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2012 Semiconductor Test Employee	Jun. 30, 2011 Semiconductor Test Employee	Mar. 31, 2011 Semiconductor Test Employee	Sep. 30, 2012 Systems Test Group Employee	Sep. 30, 2012 Wireless Test Employee	Jun. 30, 2012 Q1 2011 Actions Semiconductor Test Employee	Dec. 31, 2011 Q1 2011 Actions Semiconductor Test Employee	Dec. 31, 2011 Q2 2011 Actions Semiconductor Test Employee	Dec. 31, 2011 Q2 2010 Actions Semiconductor Test	Dec. 31, 2010 Q2 2010 Actions Systems Test Group Employee	Dec. 31, 2011 Q4 2010 Actions Semiconductor Test	Dec. 31, 2010 Q4 2010 Actions Systems Test Group Employee	Dec. 31, 2011 Pre-2010 Activities	Dec. 31, 2010 Pre-2010 Activities	Dec. 31, 2010 Pre-2010 Activities Systems Test Group	Dec. 31, 2010 Pre-2010 Activities Semiconductor Test And System Test Group	Dec. 31, 2010 Q1 2010 Actions Semiconductor Test Employee	Dec. 31, 2010 Q3 2010 Actions Systems Test Group Employee	Dec. 31, 2010 Foreign Pension Plans, Defined Benefit
Restructuring Cost and Reserve
Business acquisition, contingent consideration		$ 68,500,000	$ 8,800,000
Business acquisition, contingent consideration paid			59,700,000
Restructuring and other charges			5,800,000
Acquisition Cost			4,600,000
Pension Settlement non US			1,200,000
Other gains related to pension settlement																						3,000,000
Remaining accrual for lease payments		1,100,000
Severance benefit and charges	700,000	200,000		300,000	300,000	800,000	500,000	200,000	300,000	600,000	300,000	200,000	900,000	100,000	100,000			(200,000)	500,000	400,000	400,000
Lease expiration date		Dec. 31, 2013
Unoccupied space subleased		37.00%
Reduction in employees head count	9			10	2	5	7	2	10	5	2		6		1					4	10
Early exit of leased facility						$ (400,000)										$ (500,000)	$ (2,700,000)