Acquisitions - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended												12 Months Ended						1 Months Ended	2 Months Ended			1 Months Ended	3 Months Ended
	Oct. 31, 2013	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, 2013		Dec. 31, 2012		Dec. 31, 2011		Oct. 31, 2013 ZTEC Instruments, Inc.	Dec. 31, 2013 ZTEC Instruments, Inc.	Oct. 25, 2013 ZTEC Instruments, Inc.	Oct. 25, 2013 ZTEC Instruments, Inc. Maximum	Oct. 05, 2011 Litepoint Corporation	Dec. 31, 2011 Litepoint Corporation	Dec. 31, 2013 Litepoint Corporation
Business Acquisition [Line Items]
Total purchase price																				$ 17,300,000				$ 646,000,000
Cash paid to acquire outstanding common and preferred stock																				15,100,000				572,700,000
Contingent consideration		2,230,000					388,000							2,230,000		388,000						2,200,000	5,000,000	68,900,000
Business acquisition, Contingent consideration discount rate	5.20%
Goodwill		361,792,000					349,272,000							361,792,000		349,272,000		352,778,000			12,520,000					349,272,000
Total net revenues		285,301,000	[1],[2]	433,376,000	428,889,000	280,367,000	248,404,000	[3],[4]	463,394,000	548,284,000	[5]	396,668,000	[6]	1,427,933,000	[7]	1,656,750,000	[7]	1,429,061,000	[7]		400,000				28,400,000
Income (loss) from continuing operations before taxes		35,439,000	[1],[2]	87,552,000	80,357,000	(1,426,000)	(30,285,000)	[3],[4]	103,025,000	151,992,000	[5]	41,244,000	[6]	201,922,000	[8],[9]	265,976,000	[8],[9]	214,421,000	[8],[9]		(800,000)				(20,600,000)
Fair value of assumed vested stock options																								$ 4,500,000

[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.

[7] Revenues attributable to a country are based on location of customer site.

[8] Interest income, interest expense and other, and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations.

[9] Included in income (loss) from continuing operations before taxes are charges and credits related to restructuring and other and inventory charges.