Basis of presentation and accounting policies - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Total revenues	$ 680,049	$ 714,252
Distribution
Disaggregation of Revenue [Line Items]
Total revenues	379,556	380,503
Advertising & Marketing Services
Disaggregation of Revenue [Line Items]
Total revenues	286,397	296,109
Political
Disaggregation of Revenue [Line Items]
Total revenues	3,616	27,828
Other
Disaggregation of Revenue [Line Items]
Total revenues	$ 10,480	$ 9,812