Summary of Significant Accounting Policies - Schedule of Revenue Disaggregated by Revenue Type, Geographic Region and Customer (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue:
Total revenue	$ 1,089,752	$ 1,046,487	$ 990,533
Percentage of total revenue	100.00%	100.00%	100.00%
Broadband/Cable/Satellite
Revenue:
Percentage of total revenue	54.00%	57.00%	58.00%
Telecommunications
Revenue:
Percentage of total revenue	20.00%	19.00%	19.00%
Other
Revenue:
Percentage of total revenue	26.00%	24.00%	23.00%
Americas (principally the U.S.)
Revenue:
Percentage of total revenue	85.00%	85.00%	86.00%
Europe, Middle East and Africa
Revenue:
Percentage of total revenue	11.00%	11.00%	10.00%
Asia Pacific
Revenue:
Percentage of total revenue	4.00%	4.00%	4.00%
SaaS and Related Solutions
Revenue:
Total revenue	$ 956,995	$ 926,290	$ 880,822
Software and Services
Revenue:
Total revenue	87,247	72,818	63,239
Maintenance
Revenue:
Total revenue	$ 45,510	$ 47,379	$ 46,472