Changes in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of December 31, 2013	$ (5,773)	$ 1,998
Other comprehensive income (loss)	(2,793)	(7,771)
Balance as of December 31, 2014	(8,566)	(5,773)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of December 31, 2013	(33)	(5)
Other comprehensive income (loss)	22	(28)
Balance as of December 31, 2014	(11)	(33)
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of December 31, 2013	(5,740)	2,003
Other comprehensive income (loss)	(2,815)	(7,743)
Balance as of December 31, 2014	$ (8,555)	$ (5,740)