Goodwill and Acquired Intangible Assets - Summary of Acquired Intangible Assets Subject to Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 12,478	$ 10,668
Accumulated Amortization	(4,085)	(2,677)
Net Book Value	8,393	7,991
Acquired Technology [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired	11,718	10,668
Accumulated Amortization	(4,085)	(2,677)
Net Book Value	7,633	$ 7,991
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired	480
Net Book Value	480
Trade Name and Other [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired	280
Net Book Value	$ 280