Goodwill - Schedule of Changes in Carrying Amount of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Goodwill [Line Items]
Balance as of December 31, 2018	$ 715,644
Effect of foreign currency translation	1,090
Balance as of March 31, 2019	720,360
Olson
Goodwill [Line Items]
Goodwill resulting from business combinations	3,047	[1]
Vista Limited
Goodwill [Line Items]
Goodwill resulting from business combinations	$ 579	[2]

[1] In 2019, the Company recorded changes to goodwill representing an immaterial correction of an error for income tax balances related to acquired assets and liabilities from the business combination that occurred in 2014. These balances were not significant to our previously reported financial position.

[2] Goodwill measurement period adjustment related to the settlement of the working capital adjustment under the purchase agreement.