Goodwill and Intangible Assets, Net - Components of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross	$ 3,194	$ 3,194
Accumulated Amortization	(2,608)	(2,449)
Net	$ 586	745
Weighted average remaining useful life	2 years 9 months 18 days
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Gross	$ 3,194	3,194
Accumulated Amortization	(2,608)	(2,449)
Net	$ 586	$ 745
Weighted average remaining useful life	2 years 9 months 18 days	3 years 6 months