Segment Information - Segment Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Revenue	$ 280,606	$ 318,570
Segment EBITDA	104,933	112,779
Marketing Services
Segment Reporting Information [Line Items]
Revenue	227,933	286,722
Segment EBITDA	98,631	110,078
SaaS
Segment Reporting Information [Line Items]
Revenue	37,251	31,848
Segment EBITDA	316	2,701
Thryv International
Segment Reporting Information [Line Items]
Revenue	15,422	0
Segment EBITDA	$ 5,986	$ 0