Basis of presentation and accounting policies - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 710,363	$ 731,506	$ 1,424,615	$ 1,471,833
Subscription
Disaggregation of Revenue [Line Items]
Total revenues	367,025	396,126	742,349	810,406
Advertising & Marketing Services
Disaggregation of Revenue [Line Items]
Total revenues	300,977	317,726	599,669	625,571
Political
Disaggregation of Revenue [Line Items]
Total revenues	31,643	5,991	59,471	11,282
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 10,718	$ 11,663	$ 23,126	$ 24,574