Commitments and Contingencies (Details)				1 Months Ended	3 Months Ended		12 Months Ended		27 Months Ended	49 Months Ended
	Aug. 09, 2018 USD ($)	Mar. 23, 2018 USD ($)	Dec. 08, 2008 subsidiary	Feb. 29, 2012 USD ($)	Mar. 31, 2019 USD ($) claim case	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($) claim case	Dec. 31, 2012 claim	May 10, 2019 radio_station television_station	Apr. 13, 2017 station
Loss Contingencies [Line Items]
Number of direct and indirect wholly-owned subsidiaries included in bankruptcy filing | subsidiary			110
Number of proofs of claim settled or satisfied pursuant to the terms of the plan | case					106				106
Number of complaints filed | claim										7,400
Restricted cash and cash equivalents					$ 16,607,000	$ 16,607,000	$ 16,607,000		$ 16,607,000
Number of proofs of claim subject to further evaluation and adjustments | claim					403				403
Reorganization Items					$ 1,318,000	893,000
Federal Communications Commission Regulation, Television Station Ownership Cap, Percent					39.00%				39.00%
The UHF Discount, Percent					50.00%				50.00%
FCC regulation, maximum reimbursement amount for required product modifications				$ 1,750,000,000
FCC regulation, additional reimbursement amount for required product modifications		$ 1,000,000,000
Proceeds Received From FCC Spectrum Auction								$ 191,000,000
Proceeds from FCC spectrum auction								172,000,000
Number of Stations Subject to Spectrum Frequency Transition | station												22
Capital expenditures incurred related to spectrum repack					$ 5,000,000		$ 24,000,000		$ 32,000,000
FCC reimbursements received					$ 4,000,000				$ 15,000,000
Fox Purchase Agreement
Loss Contingencies [Line Items]
Contract Termination Fee	$ 0
FCC Licenses
Loss Contingencies [Line Items]
Gain (Loss) on Disposition of Intangible Assets						$ 133,000,000
Dreamcatcher Stations
Loss Contingencies [Line Items]
Proceeds Received From FCC Spectrum Auction								$ 26,000,000
Subsequent Event
Loss Contingencies [Line Items]
FCC regulation, number of television stations authorized | television_station											39
FCC regulation, number of radio stations authorized | radio_station											1