Business Segments (Details)	12 Months Ended
	Dec. 31, 2018 television_station
Segment Reporting Information [Line Items]
Number of Television Stations	42
Segment Reporting, Disclosure of Major Customers	0.1
Television and Entertainment
Segment Reporting Information [Line Items]
Number of Television Stations	42
Television and Entertainment | Dreamcatcher
Segment Reporting Information [Line Items]
Number of Television Stations	3
Television and Entertainment | FOX Broadcasting Company Television Affiliates
Segment Reporting Information [Line Items]
Number of Television Stations	14
Television and Entertainment | CW Television
Segment Reporting Information [Line Items]
Number of Television Stations	12
Television and Entertainment | CBS Corporation Television Affiliates
Segment Reporting Information [Line Items]
Number of Television Stations	6
Television and Entertainment | American Broadcasting Company Television Affiliates
Segment Reporting Information [Line Items]
Number of Television Stations	3
Television and Entertainment | Master Distribution Services Inc.
Segment Reporting Information [Line Items]
Number of Television Stations	3
Television and Entertainment | National Broadcasting Company Television Affiliates
Segment Reporting Information [Line Items]
Number of Television Stations	2
Television and Entertainment | Independent Television Stations
Segment Reporting Information [Line Items]
Number of Television Stations	2