Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ (6,952)		$ (6,952)
Current period other comprehensive income (loss)	$ 59		$ 1	560	$ (386)
Ending balance	(6,392)			(6,392)
Other-than-temporary impairment loss on available-for-sale securities	0	500	$ 0	519	$ 0
AFS included in prepaid expenses and other current assets	1,771			1,771		$ 3,666
Net Unrealized Gain (Loss) and Impairment on Available-For- Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(518)		(518)
Current period other comprehensive income (loss)				513
Ending balance	(5)			(5)
AFS included in prepaid expenses and other current assets	15			15		$ 22
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(3,849)		(3,849)
Current period other comprehensive income (loss)				(976)
Ending balance	(4,825)			(4,825)
Unrealized Foreign Exchange Gain (Loss) on Intercompany Balance
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ (2,585)		(2,585)
Current period other comprehensive income (loss)				1,023
Ending balance	$ (1,562)			$ (1,562)