Expense (Benefit) from Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current:
Federal-U.S.	$ 3,908	$ 1,068	$ 121
State-U.S.	1,101	122	32
Total Current	5,009	1,190	(212)
Deferred:
Federal-U.S.	(1,936)	(1,604)	(353)
State-U.S.	(557)	(87)	(336)
Change in valuation allowance	5,566	6,035	3,540
Total Deferred	(2,493)	(1,691)	(689)
(Provision for) benefit from income taxes	2,516	(501)	(901)
United Kingdom
Current:
United Kingdom			(365)
Republic of Ireland and the United Kingdom
Deferred:
Ireland and United Kingdom	$ (5,566)	$ (6,035)	$ (3,540)

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