Segment Information - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018 Segment Station	Jun. 30, 2017
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			3
Percentage of revenue generated from outside the United States	20.00%	15.00%	19.00%	15.00%
Television
Segment Reporting Information [Line Items]
Number of stations owned			55
Radio
Segment Reporting Information [Line Items]
Number of stations owned			49
Advertisements and Syndicates Radio Programming | Minimum
Segment Reporting Information [Line Items]
Number of stations owned			300