Goodwill and Intangible Assets, net - Summary of Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Cost	$ 28,470	$ 28,470
Accumulated amortization	(18,382)	(14,176)
Carrying value	10,088	14,294
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	14,660	14,660
Accumulated amortization	(7,716)	(6,017)
Carrying value	$ 6,944	$ 8,643
Weighted average remaining life (in years)	4 years 7 months 6 days	5 years 6 months
Developed technology
Finite-Lived Intangible Assets [Line Items]
Cost	$ 6,820	$ 6,820
Accumulated amortization	(5,328)	(3,963)
Carrying value	$ 1,492	$ 2,857
Weighted average remaining life (in years)	1 year 2 months 12 days	2 years 2 months 12 days
Trade names
Finite-Lived Intangible Assets [Line Items]
Cost	$ 6,990	$ 6,990
Accumulated amortization	(5,338)	(4,196)
Carrying value	$ 1,652	$ 2,794
Weighted average remaining life (in years)	4 years 1 month 6 days	4 years