Summary of Significant Accounting Policies - Schedule of Revenue Disaggregated by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Total revenue	$ 244,108	$ 251,414	$ 730,046	$ 742,063
Americas (principally the U.S.)
Disaggregation Of Revenue [Line Items]
Total revenue	210,864	218,694	637,787	643,814
Europe, Middle East, and Africa
Disaggregation Of Revenue [Line Items]
Total revenue	23,429	23,284	66,595	70,516
Asia Pacific
Disaggregation Of Revenue [Line Items]
Total revenue	$ 9,815	$ 9,436	$ 25,664	$ 27,733