Intangible Assets - Schedule of Intangible Assets, Net of Accumulated Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite Lived Intangible Assets [Line Items]
Acquired intangible asset, Net	$ 399	$ 454
Intellectual Property Rights [Member]
Finite Lived Intangible Assets [Line Items]
Acquired intangible asset, Cost	547	547
Acquired intangible asset, Accumulated Amortization	(148)	(93)
Acquired intangible asset, Net	$ 399	$ 454