Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended			12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017		Dec. 31, 2017		Dec. 31, 2016
Operating Activities
Net Income (Loss)	$ 84,438	$ (30,402)	$ 225,621	$ (115,996)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Stock-based compensation	5,000	7,000	10,511	22,093
Pension credit and contributions			(38,027)	(11,024)
Depreciation			27,056	27,498
Amortization of contract intangible assets and liabilities			440	429
Amortization of other intangible assets			83,368	83,323
Income on equity investments, net	(52,568)	(40,761)	(91,705)	(77,798)
Distributions from equity investments			158,926	149,650
Non-cash loss on extinguishment and modification of debt			0	6,823
Original issue discount payments			0	(6,873)
Write-downs of investment	0	58,800	0	180,800
Amortization of debt issuance costs and original issue discount			3,718	4,127
Gain on sales of spectrum (Note 8)	0	0	(133,197)	0
Gain on sale of business			0	(34,510)
Gain on investment transactions			(3,888)	(4,950)
Gain on sale of real estate, net			0	(300)
Other non-operating gain, net			(91)	(45)
Changes in working capital items:
Accounts receivable, net			12,917	32,074
Prepaid expenses and other current assets			(16,825)	14,659
Accounts payable			(1,857)	(8,896)
Employee compensation and benefits, accrued expenses and other current liabilities			(13,993)	(17,014)
Deferred revenue			2,801	(2,726)
Income taxes			7,271	24,756
Change in broadcast rights, net of liabilities			(28,612)	(11,893)
Deferred income taxes			17,405	(141,944)
Other, net			(898)	10,434
Net cash provided by operating activities			220,941	122,697
Investing Activities
Capital expenditures	(11,274)	(13,465)	(24,947)	(28,099)
Net proceeds from the sale of business			0	554,487
Sale of partial interest in equity investment			833	0
Proceeds from sales of real estate and other assets			58	59,751
Proceeds from the sale of investments			3,057	4,950
Other, net			3,255	805
Net cash (used in) provided by investing activities			(17,744)	591,894
Financing Activities
Long-term borrowings			0	202,694
Repayments of long-term debt			0	(589,661)
Long-term debt issuance costs			0	(1,689)
Payments of dividends			(43,847)	(542,665)
Tax withholdings related to net share settlements of share-based awards			(5,723)	(7,351)
Proceeds from stock option exercises			581	10,013
(Distributions to)/contributions from noncontrolling interests			(2)	1,003
Net cash used in financing activities			(48,991)	(927,656)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash			154,206	(213,065)
Cash, cash equivalents and restricted cash, beginning of period (1)			691,251	611,198	[1]	$ 611,198	[1]
Cash, cash equivalents and restricted cash, end of period	845,457	398,133	845,457	398,133		691,251
Cash, Cash Equivalents and Restricted Cash are Comprised of:
Cash and cash equivalents	828,850	380,567	828,850	380,567		673,685
Restricted cash	16,607	17,566	16,607	17,566		17,566		$ 17,566
Cash, cash equivalents and restricted cash, end of period	$ 845,457	$ 398,133	845,457	398,133		$ 691,251
Supplemental Schedule of Cash Flow Information
Interest			79,027	76,264
Income taxes, net			$ 64,294	$ 68,685

[1] (1)Cash, cash equivalents and restricted cash at the beginning of the six months ended June 30, 2017 of $611 million are comprised of $595 million of cash, cash equivalents and restricted cash from continuing operations as reflected in the Company’s unaudited Condensed Consolidated Balance Sheets and $16 million of cash, cash equivalents and restricted cash reflected in current assets of discontinued operations.