Consolidated Statements of Changes in Common Shareholders' Equity - USD ($) $ in Thousands	Total	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Class A Common Stock [Member] Common Stock [Member]	Class B Common Stock [Member] Common Stock [Member]
As of at Dec. 31, 2013	$ 3,300,288	$ 288,129	$ 4,782,777	$ 699,494	$ (2,490,333)	$ 221	$ 1,169	$ 18,831
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the year	1,293,260		1,293,260
Acquisition of redeemable noncontrolling interest	0
Net income attributable to noncontrolling interest	0		(497)			497
Net income (loss) attributable to redeemable noncontrolling interests	1,080		1,080
Distribution to noncontrolling interests	(242)					(242)
Dividends paid on common stock	(67,267)		(67,267)
Dividends paid on redeemable preferred stock	(847)		(847)
Repurchase of Class B common stock	(1,165,427)				(1,165,427)
Issuance of Class B common stock, net of restricted stock award forfeitures	7,098	(3,186)			10,284
Amortization of unearned stock compensation and stock option expense	18,291	18,291
Other comprehensive loss, net of income taxes	(246,014)			(246,014)
Conversion of Class A common stock to Class B common stock	0						(194)	194
Taxes arising from employee stock plans	555	555
Other	0
As of at Dec. 31, 2014	3,140,775	303,789	6,008,506	453,480	(3,645,476)	476	975	19,025
As of at Dec. 31, 2013	5,896
Increase (Decrease) in Temporary Equity [Roll Forward]
Acquisition of redeemable noncontrolling interest	17,108
Net income (loss) attributable to redeemable noncontrolling interests	(1,080)
Other	(20)
As of at Dec. 31, 2014	21,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the year	(99,220)		(99,220)
Contribution of noncontrolling interest to a joint venture	(476)					(476)
Net income (loss) attributable to redeemable noncontrolling interests	(1,435)		(1,435)
Change in redemption value of redeemable noncontrolling interests	(2,601)	(2,601)
Dividends paid on common stock	(53,090)		(53,090)
Dividends paid on redeemable preferred stock	(631)		(631)
Repurchase of Class B common stock	(22,979)				(22,979)
Issuance of Class B common stock, net of restricted stock award forfeitures	6,665	(13,244)			19,909
Amortization of unearned stock compensation and stock option expense	57,115	57,115
Other comprehensive loss, net of income taxes	(138,800)
Other comprehensive loss, net of income taxes	(139,658)			(139,658)
Conversion of Class A common stock to Class B common stock	0						(11)	11
Spin-Off of Cable ONE	(398,310)	7,285	(406,453)	858
Taxes arising from employee stock plans	4,543	4,543
Other	0
As of at Dec. 31, 2015	2,490,698	356,887	5,447,677	314,680	(3,648,546)	0	964	19,036
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (loss) attributable to redeemable noncontrolling interests	1,435
Change in redemption value of redeemable noncontrolling interests	2,601
Other	17
As of at Dec. 31, 2015	25,957
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) for the year	169,458		169,458
Net income (loss) attributable to redeemable noncontrolling interests	(868)		(868)
Change in redemption value of redeemable noncontrolling interests	(3,026)	(3,026)
Dividends paid on common stock	(27,325)		(27,325)
Dividends paid on redeemable preferred stock	0
Repurchase of Class B common stock	(108,948)				(108,948)
Issuance of Class B common stock, net of restricted stock award forfeitures	(53)	(697)			644
Amortization of unearned stock compensation and stock option expense	14,717	14,717
Other comprehensive loss, net of income taxes	(78,194)			(78,194)
Taxes arising from employee stock plans	558	558
Purchase of redeemable noncontrolling interest	0
Exchange of redeemable noncontrolling interest	(4,076)	(4,076)
As of at Dec. 31, 2016	2,452,941	$ 364,363	$ 5,588,942	$ 236,486	$ (3,756,850)	$ 0	$ 964	$ 19,036
Increase (Decrease) in Temporary Equity [Roll Forward]
Net income (loss) attributable to redeemable noncontrolling interests	868
Change in redemption value of redeemable noncontrolling interests	3,026
Purchase of redeemable noncontrolling interest	(24,031)
Exchange of redeemable noncontrolling interest	(5,770)
As of at Dec. 31, 2016	$ 50