Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended												6 Months Ended				9 Months Ended	12 Months Ended
	Dec. 31, 2013		Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Sep. 30, 2010	Dec. 31, 2013 Y	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Line Items]
Depreciation over life to cost of revenues and selling and administrative expenses, years																		6
Net book value of internally manufactured test systems sold																		$ 9,000,000	$ 6,000,000	$ 7,800,000
Percentage of common stock price																		85.00%	85.00%	85.00%
Stock options term																		7 years
Restricted stock unit awards granted																		4 years
Restricted stock unit award granted after one year																		1 year
Award vesting on the first anniversary																		100.00%
Maximum percent of shares allowed to purchase	10.00%																	10.00%
Fair market value																		25,000
Maximum number of shares allowed to purchase																		6,000
Stock options granted																		213,000	151,000	145,000
Weighted average grant date fair value													$ 3.42	$ 4.09	$ 4.01	$ 3.66		$ 6.09	$ 6.85	$ 6.74
Number of shares available for grant	14,213,000					6,414,000							6,414,000		8,205,000			14,213,000	6,414,000	8,205,000	9,851,000
Income tax (benefit) provision	13,096,000	[1],[2]	18,093,000	13,801,000	(8,015,000)	(13,742,000)	[3],[4]	14,384,000	40,605,000	[5]	7,680,000	[6]						36,975,000	48,927,000	(129,536,000)
Advertising costs																		1,700,000	1,600,000	1,000,000
Gains and losses on foreign exchange contracts																		6,900,000	4,500,000	900,000
Exercise price																	$ 5.48
Call option, shares																	34,700,000
Warrant price	7.67																	7.67
Foreign currency translation reclassification adjustment included in net income																				2,266,000
Discrete Tax
Summary Of Significant Accounting Policies [Line Items]
Income tax (benefit) provision					$ 6,700,000
Stock Options
Summary Of Significant Accounting Policies [Line Items]
Percentage of common stock price																		100.00%
Period of stock granted to employees and executive officers vest in equal installments																		4 years
Employee Stock Purchase Plan
Summary Of Significant Accounting Policies [Line Items]
Number of shares available for grant	6,400,000																	6,400,000

[1] Interest expense and other includes a $34.2 million gain from the sale of an equity investment.

[2] In the fourth quarter ended December 31, 2013, pension and post retirement net actuarial gains increased gross profit and net income by $2.7 million and $9.1 million, respectively. See Note B: "Accounting Policies" for a discussion of our accounting policy.

[3] In the fourth quarter ended December 31, 2012, we corrected prior period income tax provision (benefit) errors that resulted in a $0.2 million income tax provision. These errors were not individually or in aggregate material to the fourth quarter of 2012 or any prior period.

[4] In the fourth quarter ended December 31, 2012, pension and postretirement actuarial losses decreased gross profit and net income by $8.1 million and $18.3 million, respectively. See Note B: "Accounting Policies" for a discussion of our accounting policy.

[5] Restructuring and other includes $0.3 million of severance charges related to headcount reductions of 10 people in Semiconductor Test and ($6.5) million fair value adjustment to decrease the LitePoint acquisition contingent consideration.

[6] Restructuring and other includes a ($1.8) million fair value adjustment to decrease the LitePoint acquisition contingent consideration.