FCC Regulatory Matters - Additional Information (Details)			1 Months Ended	12 Months Ended
	Oct. 17, 2017 USD ($)	Apr. 13, 2017 TelevisionStation	Nov. 30, 2017 TelevisionStation	Dec. 31, 2017 USD ($) TelevisionStation
FCC Regulatory Matters [Line Items]
Maximum percentage of US television household reach				39.00%
Percentage reach of ultra high frequency station				50.00%
Effective date of reinstating the ultra high frequency discount				Jun. 15, 2017
Date of abolishing the UHF discount				Aug. 24, 2016
Number of stations owned		11
Number of stations, channels share with another station		8
Number of stations to move to very high frequency channels		2
Number of stations went off the air			1
Number of stations required to cease broadcasting				10
Maximum amount allocated by Congress for reimbursement of repack costs industry-wide | $				$ 1,750,000,000
Total costs submitted for repack reimbursement | $	$ 1,860,000,000
Excess over maximum amount allocated by Congress for reimbursement of repack costs industry-wide | $	$ 100,000,000
Nexstar [Member]
FCC Regulatory Matters [Line Items]
Number of stations owned		10
Number of full power stations repacked				61
Consolidated VIEs [Member]
FCC Regulatory Matters [Line Items]
Number of stations owned		1
Number of full power stations repacked				17