CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Statement of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
Total revenues	$ 766,260	$ 644,532	$ 2,161,756	$ 1,923,702
Media program and production expenses	303,782	268,330	893,189	796,218
Selling, general and administrative	188,903	159,436	540,877	456,830
Depreciation, amortization and other operating expenses	115,765	113,319	330,983	290,730
Total operating expenses	608,450	541,085	1,765,049	1,543,778
Operating income	157,810	103,447	396,707	379,924
Equity in earnings of consolidated subsidiaries	0	0	0	0
Interest expense	(75,753)	(51,743)	(237,766)	(160,020)
Other income (expense)	(19,705)	(2,020)	(42,210)	(24)
Total other expense, net	(95,458)	(53,763)	(279,976)	(160,044)
Income tax benefit (provision)	2,648	(17,118)	21,573	(70,577)
NET INCOME	65,000	32,566	138,304	149,303
Net income attributable to the noncontrolling interests	(1,125)	(1,929)	(3,264)	(16,820)
NET INCOME ATTRIBUTABLE TO SINCLAIR BROADCAST GROUP	63,875	30,637	135,040	132,483
Comprehensive income	65,000	32,566	138,304	149,303
Reportable legal entities | Sinclair Broadcast Group, Inc.
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
Total revenues	0	0	0	0
Media program and production expenses	0	0	0	0
Selling, general and administrative	2,653	2,027	8,124	5,615
Depreciation, amortization and other operating expenses	19	247	58	738
Total operating expenses	2,672	2,274	8,182	6,353
Operating income	(2,672)	(2,274)	(8,182)	(6,353)
Equity in earnings of consolidated subsidiaries	65,301	32,196	139,684	136,311
Interest expense	0	(10)	(1)	(81)
Other income (expense)	296	(92)	1,619	731
Total other expense, net	65,597	32,094	141,302	136,961
Income tax benefit (provision)	950	817	1,920	1,875
NET INCOME	63,875	30,637	135,040	132,483
Net income attributable to the noncontrolling interests	0	0	0	0
NET INCOME ATTRIBUTABLE TO SINCLAIR BROADCAST GROUP	63,875	30,637	135,040	132,483
Comprehensive income	63,875	30,637	135,040	132,483
Reportable legal entities | Sinclair Television Group, Inc.
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
Total revenues	6	0	6	0
Media program and production expenses	1	0	1	0
Selling, general and administrative	31,546	23,534	79,885	64,903
Depreciation, amortization and other operating expenses	1,227	1,591	3,612	4,967
Total operating expenses	32,774	25,125	83,498	69,870
Operating income	(32,768)	(25,125)	(83,492)	(69,870)
Equity in earnings of consolidated subsidiaries	154,948	90,445	454,881	274,850
Interest expense	(74,031)	(50,247)	(232,833)	(154,330)
Other income (expense)	(6,368)	1,869	(817)	2,392
Total other expense, net	74,549	42,067	221,231	122,912
Income tax benefit (provision)	27,660	25,364	65,114	75,105
NET INCOME	69,441	42,306	202,853	128,147
Net income attributable to the noncontrolling interests	0	0	0	0
NET INCOME ATTRIBUTABLE TO SINCLAIR BROADCAST GROUP	69,441	42,306	202,853	128,147
Comprehensive income	69,441	42,306	202,853	128,147
Reportable legal entities | Guarantor Subsidiaries and KDSM, LLC
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
Total revenues	714,387	614,881	2,020,201	1,833,208
Media program and production expenses	288,651	255,293	848,005	761,720
Selling, general and administrative	149,898	130,289	440,380	377,177
Depreciation, amortization and other operating expenses	77,851	88,293	168,838	266,371
Total operating expenses	516,400	473,875	1,457,223	1,405,268
Operating income	197,987	141,006	562,978	427,940
Equity in earnings of consolidated subsidiaries	(611)	114	(366)	257
Interest expense	(1,029)	(1,013)	(2,991)	(3,557)
Other income (expense)	(15,048)	(2,673)	(42,753)	(4,071)
Total other expense, net	(16,688)	(3,572)	(46,110)	(7,371)
Income tax benefit (provision)	(24,999)	(46,987)	(58,283)	(143,059)
NET INCOME	156,300	90,447	458,585	277,510
Net income attributable to the noncontrolling interests	0	0	0	0
NET INCOME ATTRIBUTABLE TO SINCLAIR BROADCAST GROUP	156,300	90,447	458,585	277,510
Comprehensive income	156,300	90,447	458,585	277,510
Reportable legal entities | Non- Guarantor Subsidiaries
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
Total revenues	76,827	47,676	206,568	148,690
Media program and production expenses	35,975	29,376	101,170	88,296
Selling, general and administrative	5,318	3,582	13,954	9,135
Depreciation, amortization and other operating expenses	38,863	24,018	163,095	20,702
Total operating expenses	80,156	56,976	278,219	118,133
Operating income	(3,329)	(9,300)	(71,651)	30,557
Equity in earnings of consolidated subsidiaries	0	0	0	0
Interest expense	(4,740)	(4,968)	(13,933)	(16,740)
Other income (expense)	1,415	(1,124)	(259)	924
Total other expense, net	(3,325)	(6,092)	(14,192)	(15,816)
Income tax benefit (provision)	(963)	3,688	12,822	(4,498)
NET INCOME	(7,617)	(11,704)	(73,021)	10,243
Net income attributable to the noncontrolling interests	(1,132)	(1,730)	(3,456)	(16,608)
NET INCOME ATTRIBUTABLE TO SINCLAIR BROADCAST GROUP	(8,749)	(13,434)	(76,477)	(6,365)
Comprehensive income	(7,617)	(11,704)	(73,021)	10,243
Eliminations
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
Total revenues	(24,960)	(18,025)	(65,019)	(58,196)
Media program and production expenses	(20,845)	(16,339)	(55,987)	(53,798)
Selling, general and administrative	(512)	4	(1,466)	0
Depreciation, amortization and other operating expenses	(2,195)	(830)	(4,620)	(2,048)
Total operating expenses	(23,552)	(17,165)	(62,073)	(55,846)
Operating income	(1,408)	(860)	(2,946)	(2,350)
Equity in earnings of consolidated subsidiaries	(219,638)	(122,755)	(594,199)	(411,418)
Interest expense	4,047	4,495	11,992	14,688
Other income (expense)	0	0	0	0
Total other expense, net	(215,591)	(118,260)	(582,207)	(396,730)
Income tax benefit (provision)	0	0	0	0
NET INCOME	(216,999)	(119,120)	(585,153)	(399,080)
Net income attributable to the noncontrolling interests	7	(199)	192	(212)
NET INCOME ATTRIBUTABLE TO SINCLAIR BROADCAST GROUP	(216,992)	(119,319)	(584,961)	(399,292)
Comprehensive income	$ (216,999)	$ (119,120)	$ (585,153)	$ (399,080)