Schedule of Condensed Consolidated Statements of Operations (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2011
Change In Accounting Principle
Gain on disposal of discontinued operations, tax	$ 4,578	[1],[2]	$ 4,578	[3]	$ 4,578	[4]	$ 4,578	[5]	$ 4,578
Originally Reported
Change In Accounting Principle
Gain on disposal of discontinued operations, tax									4,578
As Adjusted
Change In Accounting Principle
Gain on disposal of discontinued operations, tax									$ 4,578

[1] Restructuring and other, net includes $0.5 million of charges related to pension settlement and $3.3 million to the acquisition of LitePoint.

[2] In the fourth quarter ended December 31, 2011, the change in recognizing pension and postretirement benefit plans expense, as a result of the mark-to-market adjustments, decreased gross profit and net income by $2.4 million and $6.1 million, respectively. See Note B: "Accounting Policies" for a discussion of our accounting policy.

[3] Restructuring and other, net includes $1.4 million of charges related to the acquisition of LitePoint.

[4] Restructuring and other, net includes $0.3 million of severance charges related to headcount reductions of approximately 2 people in Semiconductor Test and $0.7 million related to pension settlement charges.

[5] Restructuring and other, net includes $0.8 million of severance charges related to headcount reductions of approximately 5 people in Semiconductor Test and $(0.4) million credit related to early exit of previously impaired leased facilities in Westford and North Reading, Massachusetts.