The Company and Significant Accounting Policies - Summary of Components of AOCI (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income (loss)	$ (1,412)
Other comprehensive income (loss)	1,000
Income tax (expense) benefit	(200)
Total other comprehensive income (loss)	793	$ (949)
Accumulated other comprehensive income (loss)	(619)
Foreign Currency Translation
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income (loss)	(400)
Accumulated other comprehensive income (loss)	(400)
Marketable Securities
Accumulated Other Comprehensive Income Loss [Line Items]
Accumulated other comprehensive income (loss)	(1,000)
Other comprehensive income (loss)	1,000
Income tax (expense) benefit	(200)
Total other comprehensive income (loss)	800
Accumulated other comprehensive income (loss)	$ (200)