Goodwill and Intangible Assets, Net - Net Carrying Amount of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 4,568	$ 6,318
Intangible assets acquired	102,000
Amortization	(12,282)	(1,750)	$ (2,200)
Ending balance	94,286	4,568	6,318
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	3,363	4,449
Intangible assets acquired	93,260
Amortization	(8,097)	(1,086)
Ending balance	88,526	3,363	4,449
Developed Technology
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	1,048	1,486
Intangible assets acquired	8,570
Amortization	(4,086)	(438)
Ending balance	5,532	1,048	1,486
Trade Name
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	157	273
Intangible assets acquired	170
Amortization	(99)	(116)
Ending balance	228	157	273
Other
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	0	110
Intangible assets acquired	0
Amortization	0	(110)
Ending balance	$ 0	$ 0	$ 110