Change in Accumulated Other Comprehensive Income (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2015	$ 122,748
Other comprehensive income	(930)
Balance at September 30, 2016	166,522
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2015	(8,566)
Balance at September 30, 2016	(9,496)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2015	(11)
Other comprehensive income	89
Balance at September 30, 2016	78
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31, 2015	(8,555)
Other comprehensive income	(1,019)
Balance at September 30, 2016	$ (9,574)