Income Taxes - Newsday and Chicago Cubs Transactions (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Oct. 27, 2009
New Cubs LLC
Income Tax Contingency [Line Items]
Ownership percentage in common stock by third party							95.00%
Ownership percentage in common stock							5.00%
Income taxes paid					$ 50
Deferred tax liability	$ 158			$ 158	149
New Cubs LLC | Tax Year 2009
Income Tax Contingency [Line Items]
IRS proposed tax					182
IRS proposed gross valuation misstatement penalty					73
After-tax interest on proposed tax and penalty					48
Estimated federal income taxes before interest and penalties					225
Newsday LLC
Income Tax Contingency [Line Items]
Net Adjustment to Uncertain Tax Position, Current			$ 102			$ 102
Income tax reserves			125
Reduction in deferred income tax liabilities			23
Adjustment to Deferred Income Tax Liability for Changes in Tax Basis	1	$ 3	$ 91			$ 88
Payment for income tax, interest and penalties				122
Expected future payment for income tax, interest and penalties	$ 4			$ 4	4
Newsday LLC | Tax Year 2008
Income Tax Contingency [Line Items]
Estimated federal income taxes before interest and penalties					190
IRS, accuracy-related penalty					$ 38