Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2011		Dec. 31, 2011	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Net revenues			$ 9,086	$ 42,488
Income from discontinued operation before income taxes	1,278	[1]	1,278	5,406
Gain from disposal of discontinued operation before income taxes			28,949
Income tax provision			4,311	278
Income from discontinued operations			$ 25,916	$ 5,128

[1] 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.