Goodwill and Intangible Assets, Net - Acquisition-Related Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	$ 5,873
Intangible assets, accumulated amortization	(1,219)
Intangible assets, net carrying amount	4,654
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	4,886	$ 2,188
Intangible assets, accumulated amortization	(1,157)	(881)
Intangible assets, net carrying amount	3,729	$ 1,307
Technology
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	987
Intangible assets, accumulated amortization	(62)
Intangible assets, net carrying amount	$ 925