Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 1,784,401	$ 1,109,435	$ 1,421,374	$ 1,784,401
Marketing Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,659,786	979,611	1,292,795	1,659,786
Marketing Services | PYP
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	798,838	443,315	605,952
Marketing Services | IYP
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	379,687	280,750	339,416
Marketing Services | SEM
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	328,814	167,770	232,345
Marketing Services | Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	152,447	87,776	115,082
SaaS
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	124,615	129,824	128,579	$ 124,615
SaaS | Thryv Platform
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	111,875	90,923	96,405
SaaS | Thryv Leads and Add-ons
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 12,740	$ 38,901	$ 32,174