Provision for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Income Taxes [Line Items]
Current	$ 52	$ 52	$ (9,928)
Deferred	(10,572)		10,494
Total U.S.	(10,520)	52	566
Current
Deferred	(52)	(52)	(52)
Total Foreign	(52)	(52)	(52)
Provision for income taxes	$ (10,572)	$ 0	$ 514