Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Broadcast rights	$ 43,131	$ 53,249
Postretirement benefits other than pensions	1,736	1,970
Stock-based compensation and other employee benefits	11,747	13,995
Pensions	98,980	93,913
Deferred gain on spectrum	0	49,103
Other accrued liabilities	8,339	9,630
Other future deductible items	12,959	14,479
Net operating loss carryforwards	1,067	1,436
Accounts receivable	1,149	1,240
Deferred Tax Assets, Gross	179,108	239,015
Valuation allowance	(609)	(633)
Total deferred tax assets	178,499	238,382
Net intangible assets	357,353	370,284
Investments	213,887	209,751
Deferred gain on partnership contributions	69,326	96,076
Net properties	78,845	70,445
Deferred gain on spectrum	33,012	0
Total deferred tax liabilities	752,423	746,556
Net deferred tax liabilities	$ 573,924	$ 508,174