Segment Information - Disaggregation of Revenue Generating Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 430,906	$ 292,163
Core advertising
Disaggregation of Revenue [Line Items]
Total operating revenues	240,994	173,361
Political
Disaggregation of Revenue [Line Items]
Total operating revenues	18,720	880
Retransmission and carriage
Disaggregation of Revenue [Line Items]
Total operating revenues	138,950	87,283
Other
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 32,242	$ 30,639