Basis of presentation and accounting policies - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 714,252	$ 740,327
Subscription
Disaggregation of Revenue [Line Items]
Total revenues	375,324	414,280
Advertising & Marketing Services
Disaggregation of Revenue [Line Items]
Total revenues	298,692	307,845
Political
Disaggregation of Revenue [Line Items]
Total revenues	27,828	5,291
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 12,408	$ 12,911