Acquisitions, Intangible Assets and Goodwill - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Acquisition intangible assets, net, Gross Carrying Amount	$ 108,231	$ 75,775
Acquisition intangible assets, net, Accumulated Amortization	(72,115)	(66,451)
Acquisition intangible assets, net, Net Carrying Amount	36,116	9,324
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Acquisition intangible assets, net, Gross Carrying Amount	61,419	47,696
Acquisition intangible assets, net, Accumulated Amortization	(44,357)	(42,410)
Acquisition intangible assets, net, Net Carrying Amount	17,062	5,286
Trade Name
Finite Lived Intangible Assets [Line Items]
Acquisition intangible assets, net, Gross Carrying Amount	8,151	6,072
Acquisition intangible assets, net, Accumulated Amortization	(6,105)	(5,796)
Acquisition intangible assets, net, Net Carrying Amount	2,046	276
Developed Technology
Finite Lived Intangible Assets [Line Items]
Acquisition intangible assets, net, Gross Carrying Amount	38,661	22,007
Acquisition intangible assets, net, Accumulated Amortization	(21,653)	(18,245)
Acquisition intangible assets, net, Net Carrying Amount	$ 17,008	$ 3,762