Goodwill and Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 128,728	[1]	$ 82,534
Goodwill acquired	26,063		39,668
Foreign currency translation adjustments	(5,946)		6,526
Goodwill, ending balance	$ 148,845		$ 128,728	[1]

[1] As adjusted to reflect the impact of the full retrospective adoption of Topic 606.