Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Balance as of January 1,		$ 46,860	$ 43,469	$ 20,451
Purchase price adjustments to goodwill retroactively applied	[1]			6,006
Goodwill acquired during the year			3,431	17,012
Translation adjustments		(84)	(40)
Balance as of December 31,		$ 46,776	$ 46,860	$ 43,469

[1] The purchase price adjustments identified during 2014 have been retroactively applied as of December 31, 2013.