Other Matters - Narrative (Details)	1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 30, 2017 USD ($) station phase	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Mar. 23, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Number of stations assigned new channels | station	13
Authorized reimbursement amount	$ 1,750,000,000.00
Authorized reimbursement amount, repacking fund				$ 1,000,000,000
Authorized reimbursement amount, repacking fund, full power, class a stations and multichannel distributors				$ 750,000,000
Repacking period	39 months
Number of repacking phases | phase	10
Capital expenditures incurred			$ 7,900,000
Amount purchased			6,600,000
FCC reimbursements received			$ 5,100,000
Amounts reimbursed as a percentage of total costs	92.50%
Severance charges		$ 7,300,000