Income Taxes - Narrative (Details) - USD ($)	3 Months Ended								6 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 02, 2015	Dec. 28, 2014	Oct. 27, 2009	Jul. 29, 2008
Federal Income Tax Note
Income tax (benefit) expense	$ (219,767,000)	$ (20,087,000)	$ (9,905,000)	$ (51,614,000)	$ 43,280,000	$ 73,871,000	$ 214,856,000	$ 15,195,000		$ (301,373,000)	$ 347,202,000	$ 25,918,000
Impact of federal and state rate changes										262,851,000	0	0
Income tax settlements and other adjustments, net										634,000	179,558,000	(7,842,000)
Effective Income Tax Rate Reconciliation, Tax Settlement, Other, Amount											11,000,000
Impairment charge, goodwill										0	0
Undistributed foreign earnings	100,000				100,000				$ 100,000	100,000	100,000	200,000
Operating loss carryforwards	50,000,000				56,000,000				56,000,000	50,000,000	56,000,000
Deferred Tax Liabilities, Investments	209,751,000				399,103,000				399,103,000	209,751,000	399,103,000
Unrecognized tax benefits	23,322,000				22,532,000				22,532,000	23,322,000	22,532,000	33,632,000		$ 18,852,000
Favorable adjustment that would have been recognized	20,000,000				17,000,000				17,000,000	20,000,000	17,000,000
Company's accrued interest and penalties related to uncertain tax positions	1,000,000				1,000,000				1,000,000	1,000,000	1,000,000
Decrease in Unrecognized Tax Benefits is Reasonably Possible	11,000,000									$ 11,000,000
Minimum
Federal Income Tax Note
Operating Loss Carryforwards, Expiration Date										Jan. 01, 2019
Maximum
Federal Income Tax Note
Operating Loss Carryforwards, Expiration Date										Dec. 31, 2029
Television and Entertainment
Federal Income Tax Note
Impairment charge, goodwill												381,000,000
Newsday LLC
Federal Income Tax Note
Income tax settlements and other adjustments, net											191,000,000
Investment owned, percent																97.00%
Investment ownership, percentage													3.00%			3.00%
Income Taxes Paid												$ 136,000,000
Deferred Tax Liabilities, Investments													$ 101,000,000
Net Adjustment to Uncertain Tax Position, Current							102,000,000
Liability for Uncertainty in Income Taxes, Current							125,000,000
Increase (Decrease) in Deferred Income Taxes							(23,000,000)
Adjustment to Deferred Income Tax Liability for Changes in Tax Basis					3,000,000		$ 91,000,000
Income Tax Examination, Interest Expense					1,000,000
Payment for income tax, interest and penalties									122,000,000
Expected future payment for income tax, interest and penalties	4,000,000									$ 4,000,000
Company's accrued interest and penalties related to uncertain tax positions	1,000,000				80,000,000				80,000,000	1,000,000	80,000,000
Newsday LLC | Tax Year 2008
Federal Income Tax Note
Income tax examination, estimate of possible loss before penalties and interest										190,000,000
Income tax examination, penalties										38,000,000
New Cubs LLC
Federal Income Tax Note
Investment owned, percent															95.00%
Investment ownership, percentage															5.00%
Income Taxes Paid										53,000,000
Deferred Tax Liabilities, Investments	$ 96,000,000				$ 158,000,000				$ 158,000,000	96,000,000	$ 158,000,000
New Cubs LLC | Tax Year 2009
Federal Income Tax Note
Income Tax Examination, Estimate of Possible Taxes										182,000,000
Income Tax Examination, Estimate of Possible Penalties										73,000,000
Income Tax Examination, Estimate of Possible Interest										63,000,000
Income tax examination, estimate of possible loss										225,000,000
Domestic Tax Authority
Federal Income Tax Note
Impact of federal and state rate changes										256,000,000
State and Local Jurisdiction
Federal Income Tax Note
Impact of federal and state rate changes										$ 7,000,000