Components of Income Tax Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current income tax expense (benefit):
Foreign	$ 163	$ (628)	$ 729
U.S. Federal	859	(3,765)	1,889
Total current income tax expense (benefit)	1,022	(4,393)	2,618
Deferred income tax expense (benefit):
U.S. Federal	(3)	(1,463)	169
Total deferred income tax expense (benefit)	(3)	(1,463)	169
Total income tax expense (benefit)	$ 1,019	$ (5,856)	$ 2,787