Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Disclosure Reconciliation Of Beginning And Ending Amount Of Unrecognized Tax Benefits [Abstract]
Balance at January 1	$ 2,886	$ 2,800
Additions based on tax positions related to the current year	352	319
Additions for tax positions of prior years		4
Reductions in prior year tax positions		(125)
Other reductions in prior year tax positions	(15)	(112)
Balance at December 31	$ 3,223	$ 2,886