Goodwill and Intangible Assets, Net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 30,370	$ 35,513
Accumulated amortization	(8,793)	(12,316)
Net carrying amount	21,577	23,197
Developed Technology
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	3,982	5,090
Accumulated amortization	(2,453)	(3,225)
Net carrying amount	$ 1,529	$ 1,865
Developed Technology | Weighted-Average
Finite Lived Intangible Assets [Line Items]
Weighted average life (years)	3 years 14 days	3 years 14 days
Tradenames
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 2,546	$ 3,193
Accumulated amortization	(1,114)	(1,526)
Net carrying amount	$ 1,432	$ 1,667
Tradenames | Weighted-Average
Finite Lived Intangible Assets [Line Items]
Weighted average life (years)	4 years 6 months 3 days	4 years 6 months 3 days
Non-compete
Finite Lived Intangible Assets [Line Items]
Gross carrying amount		$ 240
Accumulated amortization		(230)
Net carrying amount		$ 10
Non-compete | Weighted-Average
Finite Lived Intangible Assets [Line Items]
Weighted average life (years)		2 years
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 23,842	$ 26,990
Accumulated amortization	(5,226)	(7,335)
Net carrying amount	$ 18,616	$ 19,655
Customer Relationships | Weighted-Average
Finite Lived Intangible Assets [Line Items]
Weighted average life (years)	6 years 4 months 20 days	6 years 4 months 20 days